Skocz do pozycji: 1.

Tytuł:

Uwagi na marginesach "Dzieł" sir Joshuy Reynoldsa, wyd. Edmond Malone, Londyn 1798
Annotations to Reynolds “Discourses, ed. Edmond Malone, Londyn 1798

Autorzy:

Blake, William
Jaźwierski, Jacek

Powiązania:

https://bibliotekanauki.pl/articles/706962.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Blake
Reynolds
Annotations
Uwagi

Opis:

Polish translation of Wiliam Blake's Annotations to Reynolds' Discourses

Źródło:

Rocznik Historii Sztuki; 2012, 37; 141-164
0080-3472

Pojawia się w:

Rocznik Historii Sztuki

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:

Uwagi na marginesach „Dzieł” sir Joshuy Reynoldsa: Williama Blake’a spor z Reynoldsem o sztukę
William Blake ’s annotations to Reynolds “Discourses ”: William Blake ’s Quarrel with Reynolds on art

Autorzy:

Jaźwierski, Jacek

Powiązania:

https://bibliotekanauki.pl/articles/707133.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

Blake
Reynolds
art theory
teoria sztuki

Opis:

William Blake’s annotations to the first volume of “The Works of Sir Joshua Reynolds” prove an excellent and at the same time fascinating source of knowledge about his views on art. They depict Blake as a rebel against the established rules in English artistic life of the late 18th and early 19th centuries. The poet identifies their origin in the beliefs and artistic policies of the first President of the Royal Academy, Sir Joshua Reynolds. This article, a commentary to the translated version (in the same volume) of “Annotations”, at its core primarily attempts to highlight theoretical and artistic issues, but does not shy away from biographical, social and political topics necessary to an understanding of Blake’s artistic and personal views. Relations between the two adversaries, strained ever since Blake’s studies at the Royal Academy in the first half of the 1780s, took on a mythical character of enmity after Reynolds’ death. Blake was the first to criticize the highly regarded Seven Discourses on Art by Reynolds, where - not always fairly – he saw proof of theoretical contradictions and the decline of art. The clash between Reynolds’ aesthetic rationalism and empiricism and Blake’s mysticism precluded the possibility of agreement. All this does not mean, however, that the dispute between Blake and Reynolds was free of paradoxes and ambiguities and that his mind was completely detached from the academicism and classicism of official English art. On the contrary. This article tries to show that, like any radical rebel, Blake largely belonged to the world from which he tried to break away, that his art grew out of 18th-century categories and can best be understood as such.

Źródło:

Rocznik Historii Sztuki; 2012, 37; 129-140
0080-3472

Pojawia się w:

Rocznik Historii Sztuki

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 3.

Tytuł:

Analysis of a cross-channel micromixer through the dynamics of tracer gradient

Autorzy:

Gonzalez, M.

Powiązania:

https://bibliotekanauki.pl/articles/281009.pdf

Data publikacji:

2016

Wydawca:

Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej

Tematy:

Low-Reynolds number flows
mixing enhancement
micromixers

Opis:

The study aims at showing how the dynamics of tracer gradient accounts for the stirring mechanism produced by a periodically forced flow relevant to practical mixing operation. The numerical simulation uses the equations for the orientation and norm of the tracer gradient and an analytic model for velocity. To a large extent, the micromixer properties over different ranges of the Strouhal number are explained through the response of the tracer gradient orientation to the tilting of strain principal axes resulting from flow forcing. The analysis also reveals a rich picture of stirring as the Strouhal number is varied.

Źródło:

Journal of Theoretical and Applied Mechanics; 2016, 54, 4; 1257-1269
1429-2955

Pojawia się w:

Journal of Theoretical and Applied Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Differences method topology of hydrodynamic pressure calculations from Reynolds equation

Autorzy:

Wierzcholski, K.

Powiązania:

https://bibliotekanauki.pl/articles/246229.pdf

Data publikacji:

2010

Wydawca:

Instytut Techniczny Wojsk Lotniczych

Tematy:

Reynolds equation
new numerical solution
urvilinear boundary conditions

Opis:

The main topic of the presented paper concerns the method of determination and calculations of the general and particular numerical solutions of modified Reynolds equation in curvilinear orthogonal coordinates for curvilinear boundary conditions for hydrodynamic pressure distributions in bearing gap. A general solution matrix was derived and determined for various orthogonal coordinates of two cooperating bearing surfaces separated by the oil existing in slide Journal bearings. From mathematical point presented method of solution of modified Reynolds equation leads this problem to resolving the partial recurrence non homogeneous, linear equation of second order with variable coefficients. As an example the numerical hydrodynamic pressure calculation for slide bearing two cylindrical surfaces limited bearing gap with various eccentricities was in this paper performed. In numerical calculations are applied the formulae and calculation algorithm derived in this paper. Moreover, presented numerical topology of calculations in this paper enables to find the optimum way of determination of pressure values for an applied difference method regarding to the stability of solutions, convergences of the obtained values with various orthogonal shapes of cooperating surfaces. An adaptation of the known numerical difference method to the various curvilinear orthogonal boundary conditions applied during the hydrodynamic pressure determination on the two various curvilinear cooperating surfaces, to be decisive after author knowledge about a new achievement consisted in presented paper.

Źródło:

Journal of KONES; 2010, 17, 4; 583-590
1231-4005
2354-0133

Pojawia się w:

Journal of KONES

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 5.

Tytuł:

Shear Stress Statistics in a Compound Channel Flow

Autorzy:

Czernuszenko, W.
Rowiński, P. M.

Powiązania:

https://bibliotekanauki.pl/articles/241044.pdf

Data publikacji:

2008

Wydawca:

Polska Akademia Nauk. Instytut Budownictwa Wodnego PAN

Tematy:

open channels
turbulence
measurements
Reynolds stresses
coherent structures

Opis:

The results of comprehensive measurements of three-dimensional turbulent velocities carried out in a laboratory compound channel are presented. Tests were performed in a two-stage channel with a smooth main channel bed consisting of concrete and rough floodplains and sloping banks. Instantaneous velocities were measured with the use of a three-component acoustic Doppler velocimeter. The main aim of the study is the recognition of structure of Reynolds stresses in turbulent open channel flows. Particular attention has been paid to bursting events such as ejections and sweeps. The bursting phenomenon occurs originally near the buffer layer and then shows a coherent or organized flow structure during its convection process. The probability density distributions of the turbulent velocities were measured at different distances from the bed in the main channel and also above the inclined walls. In the main channel, the lateral turbulent velocity is seen to follow the normal Gaussian distribution more closely than the remaining two components. Above the inclined walls, all distributions turned out to have greater skewness. The probability density distributions of correlations between velocity fluctuations were also calculated. These distributions have long tails and sharp peaks and fit the theoretical distributions very well. The structure of instantaneous Reynolds stresses was analyzed by a quadrant technique with an arbitrarily chosen threshold level. It has been shown that the largest contribution to turbulent stresses comes from the second quadrant (ejection) and the fourth quadrant (sweep). The basic temporal characteristics for quadrant events, like the average and maximum time for a zero hole size, have been determined in the study. Calculations of maximum duration times for all events reveal that times are greater for even quadrants than for odd quadrants.

Źródło:

Archives of Hydro-Engineering and Environmental Mechanics; 2008, 55, 1-2; 3-27
1231-3726

Pojawia się w:

Archives of Hydro-Engineering and Environmental Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 6.

Tytuł:

On general-purpose turbulence models in CFD

Autorzy:

Pozorski, J.

Powiązania:

https://bibliotekanauki.pl/articles/175545.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

computational fluid dynamics
turbulence modeling
Reynolds-averaged approaches

Opis:

The computational fluid dynamics (CFD) tools for various flow problems have become widespread nowadays, yet their use still needs attention and care. In particular, turbulence models are often a crucial part of flow computations undertaken with various software packages, either commercial, open-source or in-house. In the paper, an overview of available model categories is provided, together with some discussion of their advantages or drawbacks with respect to flow cases of interest.

Źródło:

Transactions of the Institute of Fluid-Flow Machinery; 2015, 127; 45-62
0079-3205

Pojawia się w:

Transactions of the Institute of Fluid-Flow Machinery

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 7.

Tytuł:

Characteristic of Vertical Reynolds Shear Stress in a Patchy Heterogeneous Open Channel

Autorzy:

Olatunji, Peter Folorunso

Powiązania:

https://bibliotekanauki.pl/articles/1177793.pdf

Data publikacji:

2018

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

Reynolds Stress
gravel
heterogeneous
open channel
patchy
turbulence
vegetation

Opis:

In turbulent flow, the Reynolds stress provides an understanding of the shear dispersion within the flow. Turbulence can be said to have an effect equivalent to the Reynolds shear stresses and are indicators of turbulence transport. This paper examined the characteristic of vertical Reynolds Shear stress in a patchy heterogeneous open channel using two experimental conditions for flexible and rigid vegetation interaction with gravel bed. The results show the value of vertical Reynolds stress decreases downstream along the channel section and as the distance from change in roughness increases. This is attributed to the effects of the bed roughness configuration (due to the preceding vegetated bed roughness) on the vertical Reynolds stress distribution. However, the position of maximum vertical Reynolds stress is located near bed over the vegetated zone. This provides an indication that the vegetated bed serves as the primary source of turbulence for the flow.

Źródło:

World Scientific News; 2018, 99; 1-14
2392-2192

Pojawia się w:

World Scientific News

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 8.

Tytuł:

A New Star-Like SurfaceTexture for Enhanced Hydrodynamic Lubrication Performance

Autorzy:

Uddin, M. S.
Liu, Y. W.
Shankar, S.

Powiązania:

https://bibliotekanauki.pl/articles/356465.pdf

Data publikacji:

2017

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

surface texturing
friction
film pressure
numerical modelling
Reynolds equation

Opis:

This paper presents a numerical modelling and optimization of a new ‘star-like’ geometric texture shape with an aim to improve tribological performance. Initial studies showed that the triangle effect is the most dominant in reducing the friction. Motivated with this, a ‘star-like’ texture shape consisting of a series of triangular spikes around the centre of the texture is proposed. It is hypothesised that by increasing the triangular effect on a texture shape, the converging micro-wedge effect is expected to increase, hence increasing the film pressure and reducing the friction. Using the well-known Reynolds boundary conditions, numerical modelling of surface texturing is implemented via finite difference method. Simulation results showed that the number of apex points of the new ‘star-like’ texture has a significant effect on the film pressure and the friction coefficient. A 6-pointed texture at a texture density of 0.4 is shown to be the optimum shape. The new optimum star-like texture reduces the friction coefficient by 80%, 64.39%, 19.32% and 16.14%, as compared to ellipse, chevron, triangle and circle, respectively. This indicates the potential benefit of the proposed new shape in further enhancing the hydrodynamic lubrication performance of slider bearing contacts.

Źródło:

Archives of Metallurgy and Materials; 2017, 62, 3; 1863-1869
1733-3490

Pojawia się w:

Archives of Metallurgy and Materials

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 9.

Tytuł:

Numerical modeling of heat transfer in Al2O3/H2O nanofluid flowing through a Bessel-like converging pipe

Autorzy:

Iweka, Chukwuka S.
Fadodun, Olatomide G.

Powiązania:

https://bibliotekanauki.pl/articles/1845460.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

nanofluid
Nusselt number
response surface methodology
Reynolds number
convergence
index

Opis:

This paper studies hydrodynamic and heat transfer performance of Al2O3/H2O nanofluid flowing through a Bessel-like converging pipe in laminar flow regime using the computational fluid dynamic approach. A parametric study was carried out on the effect of Reynolds number (300– 1200), convergence index (0-3) and nanoparticle concentration (0–3%) on the both hydrodynamic and thermal fields. The results showed the pressure drop profile along the axial length of the converging pipes is parabolic compared to the downward straight profile obtained in a straight pipe. Furthermore, an increase in convergence index, Reynolds number and nanoparticle concentration were found to enhance convective heat transfer performance. Also, a new empirical model was developed to estimates the average Nusselt number as a function of aforementioned variables. Finally, the result of the thermohydraulic performance evaluation criterion showed that the usage of Bessel-like converging pipes is advantageous at a low Reynolds number.

Źródło:

Archives of Thermodynamics; 2021, 42, 2; 121-153
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 10.

Tytuł:

Numerical modeling of heat transfer in Al2O3/H2O nanofluid flowing through a Bessel-like converging pipe

Autorzy:

Iweka, Chukwuka S.
Fadodun, Olatomide G.

Powiązania:

https://bibliotekanauki.pl/articles/1845485.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

nanofluid
nusselt number
response surface methodology
Reynolds number
convergence
index

Opis:

This paper studies hydrodynamic and heat transfer performance of Al2O3/H2O nanofluid flowing through a Bessel-like converging pipe in laminar flow regime using the computational fluid dynamic approach. A parametric study was carried out on the effect of Reynolds number (300– 1200), convergence index (0-3) and nanoparticle concentration (0–3%) on the both hydrodynamic and thermal fields. The results showed the pressure drop profile along the axial length of the converging pipes is parabolic compared to the downward straight profile obtained in a straight pipe. Furthermore, an increase in convergence index, Reynolds number and nanoparticle concentration were found to enhance convective heat transfer performance. Also, a new empirical model was developed to estimates the average Nusselt number as a function of aforementioned variables. Finally, the result of the thermohydraulic performance evaluation criterion showed that the usage of Bessel-like converging pipes is advantageous at a low Reynolds number.

Źródło:

Archives of Thermodynamics; 2021, 42, 2; 121-153
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

The Lattice Boltzmann method for fluid mixing: a comparison with the finite element method

Autorzy:

Egidi, N.
Misici, L.
Piergallini, R.
Tosi, F.

Powiązania:

https://bibliotekanauki.pl/articles/1955715.pdf

Data publikacji:

2004

Wydawca:

Politechnika Gdańska

Tematy:

lattice Boltzmann method
incompressible viscous fluid mixing
Reynolds number
numerical simulation

Opis:

In this article we study three-dimensional mixing of an incompressible viscous fluid subjected to the force of rotating blades in a vessel, with a low Reynolds number. The results obtained with the lattice Boltzmann method are compared with the ones previously obtained using the finite element method. All the qualitative and quantitative parameters of the two simulations agree.

Źródło:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2004, 8, 1; 5-15
1428-6394

Pojawia się w:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 12.

Tytuł:

Long Way Down: Making Space for an Empathic Understanding of African-American Adolescents through Literature

Autorzy:

Gray, Pennie

Powiązania:

https://bibliotekanauki.pl/articles/2031287.pdf

Data publikacji:

2020

Wydawca:

Uniwersytet Wrocławski. Oficyna Wydawnicza ATUT – Wrocławskie Wydawnictwo Oświatowe

Tematy:

multicultural literature
African-American
adolescent
Long Way Down
Jason Reynolds
poetry

Opis:

There has long been a call for more diverse representation in literature for children and adolescents in the United States, for children who read multicultural literature can both see themselves reflected in the literature they read and be exposed to authors from diverse backgrounds who can serve as role models for them. One such author is Jason Reynolds, a prolific African-American author of books for adolescents. His most recent book, Long Way Down, is the poignant story of a fifteen year old African-American young man named Will who must make a life-and-death decision. While Will could be viewed as impulsive and potentially violent due to the saturation of gang-related activity in his neighborhood, Reynolds’ crafting of the text compels the reader to reconsider this assessment and instead take a more empathic stance toward Will. More specifically, the author’s compelling use of cultural compassion, poetic form, and time flexibility combine to draw the reader into a deeper understanding of the complexities of Will’s life. This compassionate treatment of the main character creates a narrative that is appealing to young African-American readers who thirst for books that reflect their lives and that unveil the challenges they face as they navigate the violence that often plagues urban life. Long Way Down also provides a meaningful and realistic counter-narrative to an all-to-widely accepted view of African-American males as dangerous and violent.

Źródło:

Filoteknos; 2020, 10; 111-125
2657-4810

Pojawia się w:

Filoteknos

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 13.

Tytuł:

Influence of Variable Electroconductivity and Radiation on MHD Couette Flow

Autorzy:

Ngiangia, Alalibo T.
Okechukwu, Amadi

Powiązania:

https://bibliotekanauki.pl/articles/1192671.pdf

Data publikacji:

2016

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

MHD
Electrconductivity
Prandtl number
Grashof number
Reynolds Number
Radiation
Couette flow

Opis:

A study of Couette flow in cylindrical coordinate under the influence electroconductivity and magnetic field was carried out. Approximate solution of the governing equations and its analysis show decrease in temperature as a result of increase in radiation and Prandtl number. The study also reveals that increase in grashof number, Reynolds number, Prandtl number and electroconductivity result in an increase in velocity distribution while magnetic field increase, lead to a decrease in velocity. The shear stresses of the outer and inner cylinders at the wall of the plates and the heat flux is also determined.

Źródło:

World Scientific News; 2016, 47, 2; 241-253
2392-2192

Pojawia się w:

World Scientific News

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 14.

Tytuł:

Numerical investigation for convective heat transfer of nanofluid laminar flow inside a circular pipe by applying various models

Autorzy:

Saeed, Farqad Rasheed
Al-Dulaimi, Marwah Abdulkareem

Powiązania:

https://bibliotekanauki.pl/articles/1845502.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

convective heat transfer
Reynolds number
nanofluid
single-phase flow
thermophysical properties

Opis:

The work presents a numerical investigation for the convective heat transfer of nanofluids under a laminar flow inside a straight tube. Different models applied to investigate the improvement in convective heat transfer, and Nusselt number in comparison with the experimental data. The impact of temperature dependence, temperature independence, and Brownian motion, was studied through the used models. In addition, temperature distribution and velocity field discussed through the presented models. Various concentrations of nanoparticles are used to explore the results of each equation with more precision. It was shown that achieving the solution through specific models could provide better consistency between obtained results and experimental data than the others.

Źródło:

Archives of Thermodynamics; 2021, 42, 1; 71-95
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 15.

Tytuł:

Numerical investigation and sensitivity analysis of entropy generation of Al2O3/H2O nanofluid in turbulent regime using response surface methodology

Autorzy:

Fadodun, Olatomide G.
Olokuntoye, Bolanle A.
Salau, Ayodeji O.
Amosun, Adebimpe A.

Powiązania:

https://bibliotekanauki.pl/articles/240104.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

entropy production
Reynolds number
response-surface-methodology
nanofluid
single-phase flow

Opis:

This work investigates the effect of Reynolds number, nanoparticle volume ratio, nanoparticle size and entrance temperature on the rate of entropy generation in Al2O3 /H2O nanofluid flowing through a pipe in the turbulent regime. The Reynolds average Navier-Stokes and energy equations were solved using the standard k-ε turbulent model and the central composite method was used for the design of experiment. Based on the number of variables and levels, the condition of 30 runs was defined and 30 simulations were run. The result of the regression model obtained showed that all the input variables and some interaction between the variables are statistically significant to the entropy production. Furthermore, the sensitivity analysis result shows that the Reynolds number, the nanoparticle volume ratio and the entrance temperature have negative sensitivity while the nanoparticle size has positive sensitivity.

Źródło:

Archives of Thermodynamics; 2020, 41, 2; 119-146
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

The influence of the microgrooves on the hydrodynamic pressure distribution and load carrying capacity of the conical slide bearing

Autorzy:

Czaban, A.

Powiązania:

https://bibliotekanauki.pl/articles/246488.pdf

Data publikacji:

2012

Wydawca:

Instytut Techniczny Wojsk Lotniczych

Tematy:

conical slide bearing
pressure distribution
microgrooves
Reynolds equation
load carrying capacity

Opis:

The aim of this work is to determine the hydrodynamic pressure distribution in oil film and the load carrying capacities of conical slide micro bearings with grooved sleeves. The results for some bearings examples are presented. For the bearings taken into account, the Reynolds equation was solved by the method of Finite Differences. In the calculations, the Reynolds boundary condition was applied. The simulation was performed for the conical slide micro bearings with the groves parallel to the cone generating line. The function of lubrication gap height for the conical slide bearings with sleeves covered with microgrooves was assumed on the basis of existing papers. The results obtained for the analogous bearings without the microgrooves are also shown, therefore the influence of microgrooves on the conical slide micro bearings can be observed. On the basis of the results, one can conclude, that applying microgrooves on the bearing sleeve surface causes the increase of the value of hydrodynamic pressure and longitudinal and transverse components of the load carrying capacity of the bearing. Furthermore, the effect of the microgrooves and their impact is noticeable in graphs of hydrodynamic pressure distribution. The applied method of investigation of the impact of microgrooves on a bearing operation is simpler and less expensive than the experimental studies, however it is necessary to verify that the results obtained with this method are correct and whether in fact applying microgrooves, besides form facilitate lubrication, causes the improvement in bearing operating parameters.

Źródło:

Journal of KONES; 2012, 19, 3; 85-91
1231-4005
2354-0133

Pojawia się w:

Journal of KONES

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

Differential and recurrence unified reynolds equations and mega algorithm for their numerical solutions

Autorzy:

Wierzcholski, K.
Miszczak, A.

Powiązania:

https://bibliotekanauki.pl/articles/242919.pdf

Data publikacji:

2012

Wydawca:

Instytut Techniczny Wojsk Lotniczych

Tematy:

partial differential form
partial recurrence form
unified Reynolds equation
mega algorithm

Opis:

The objective of the research under the paper topic is an analytical, unified formulation of a new standardized view of general solution of hydrodynamic problem using algorithm to determine changes of the components of the velocity vector, the distributions of hydrodynamic pressure, load carrying capacity, of slide bearings with cooperating curvilinear, orthogonal surfaces that are lubricated with a various non-Newtonian lubricants. In this paper for non- Newtonian lubricants are questioning the hitherto prevailing assumptions using in hydrodynamic theory of lubrication such as constant value of lubricant viscosity and pressure in the thickness of lubricating gap i.e. in gap height direction. Finally, the non-homogeneous partial differential equation generated with variable coefficients that is the result of the various boundary conditions being imposed that are different for each problem solved is an equation that determines the distributions of hydrodynamic pressure values. This equation is to be written in the form of a unified non-homogenous partial recurrence equation with variable coefficients. The Authors foresee that a mega-algorithm will be developed for the solution of this equation in a numerical form. This equation in particular cases is an equivalent of modified Reynolds equations in the research that has been conducted so far concerning the hydrodynamic theory of lubrication.

Źródło:

Journal of KONES; 2012, 19, 4; 643-650
1231-4005
2354-0133

Pojawia się w:

Journal of KONES

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Autobiografikcja. Eksperymenty z życiopisaniem od przełomu wieków po modernizm
Autobiografiction. Experimental Life-Writing from the Turn of the Century to Modernism

Autorzy:

Saunders, Max
Sobolewska, Agnieszka

Powiązania:

https://bibliotekanauki.pl/articles/1431045.pdf

Data publikacji:

2020

Wydawca:

Uniwersytet Szczeciński. Wydawnictwo Naukowe Uniwersytetu Szczecińskiego

Tematy:

Stephen Reynolds
autobiografiction
fact
fiction
life-writing
autobiografikcja
fakt
fikcja
życiopisanie

Opis:

Artykuł porusza rozległy, a przy tym zaskakująco niedoinwestowany temat związków autobiografii i fikcji w okresie między rokiem 1880 a 1930. Jego istotą jest przeformułowanie poglądów na temat relacji między modernizmem i praktykami życiopisania. W tym celu Saunders przywołuje opublikowany w roku 1906 esej Stephena Reynoldsa, autora autobiograficznej książki A Poor Man’s House, w którym pojawia się pojęcie autobiografikcji, zaskakująco podobne do pojęć ze słownika ponowoczesnego. Saunders przygląda się rozumieniu tego terminu w czasach Reynoldsa i dowodzi jego przydatności, niedającej się sprowadzić jedynie do historycznego kontekstu jego powstania.
This essay approaches the large but surprisingly under-theorized topic of the relation between autobiography and fiction, concentrating on the period between 1880 and 1930, arguing for a new account of the relation between Modernism and life-writing. It introduces and analyses a key essay from 1906 by Stephen Reynolds, author of A Poor Man’s House, which, strikingly, coins the post-modern-sounding term ‘autobiografiction’. It argues that Reynolds’ central concept sheds light on the vexed theoretical question of the relation between autobiography and fiction, and in ways that reach further than either Reynolds or the essay’s few commentators have appreciated.

Źródło:

Autobiografia Literatura Kultura Media; 2020, 15, 2; 41-65
2353-8694
2719-4361

Pojawia się w:

Autobiografia Literatura Kultura Media

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

Characteristics of Laminar Flow in Pipelines of Homogenous Alum Sludge Approximated with use of the Vočadlo Model for Viscoplastic Liquids
Charakterystyka laminarnego płynięcia w rurociągach jednorodnych osadów pokoagulacyjnych aproksymowanych modelem cieczy plastyczno-lepkich Vočadli

Autorzy:

Kempiński, J.
Sozański, M. M.
Dymaczewski, Z.
Świerzko, R.

Powiązania:

https://bibliotekanauki.pl/articles/205416.pdf

Data publikacji:

2014

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

alum sludge
rheology
hydrotransport
Reynolds number
osad pokoagulacyjny
reologia
liczba Reynoldsa

Opis:

The study presents the manners of determination of the Darcy friction factor λ for a homogenous hydromixture of alum sludge of varied hydration and temperature for the laminar flow zone. The rheological evaluation of the hydromixture as a viscoplastic body has been conducted with use of measurements of viscosity. The curves of flow were approximated with use of the generalized Vočadlo model. The Darcy friction factor λ of the pipeline was determined with use of the non-dimensional criterion λ(Re_gen) and λ(Re, He).
Praca przedstawia sposoby określenia współczynnika oporów rurociągu λ, dla jednorodnej hydromieszaniny osadów pokoagulacyjnych o różnym uwodnieniu i różnej temperaturze, dla laminarnej strefy przepływu. Ocenę reologiczną hydromieszaniny, jako ciała plastyczno-lepkiego, wykonano na podstawie pomiarów wiskozymetrycznych, przy zastosowaniu do aproksymacji krzywych płynięcia uogólnionego modelu Vočadli. Określenie współczynnika oporu rurociągu λ przeprowadzono z wykorzystaniem bezwymiarowego kryterium λ(Re_gen) oraz λ(Re, He).

Źródło:

Archives of Environmental Protection; 2014, 40, 4; 39-51
2083-4772
2083-4810

Pojawia się w:

Archives of Environmental Protection

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

Modelowanie sił tłumiących występujących w układach perforowanych MEMS
Modelling of damping forces occurring in the perforated MEMS systems

Autorzy:

Urbanowicz, K.
Janczewski, J.

Powiązania:

https://bibliotekanauki.pl/articles/210825.pdf

Data publikacji:

2015

Wydawca:

Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego

Tematy:

MEMS
siły tłumiące
równanie Reynoldsa
perforacja
damping forces
Reynolds equation
perforation

Opis:

Na pracę wielu układów mikroelektromechanicznych MEMS duży wpływ wywierają siły tłumiące wynikające z istnienia pomiędzy płytkami tzw. filmu powietrznego. Analityczne metody szacowania tych sił występują jedynie w prostych układach. Przy bardziej złożonych kształtach bardzo pomocne są metody numeryczne, których intensywny rozwój jest szczególnie zauważalny w ostatnich latach. Wśród paru znanych na rynku programów umożliwiających analizę układów MEMS wyróżnić można program Comsol Multiphysics, który zawiera specjalistyczny moduł MEMS. Wniniejszej pracy zostanie zweryfikowana przydatność powyższego programu w modelowaniu prostych oraz złożonych płytek zawierających perforacje w postaci otworów. Celem wykonywania w płytkach otworów jest przeważnie chęć redukcji występujących sił tłumiących. Zrealizowany szereg badań analityczno-numerycznych zobrazował liczne niedoskonałości programu Comsol, które należałoby poprawić.
Operation of many micro-electromechanical systems (MEMS) is highly influenced by damping forces resulting from the existence of fluid film between the MEMS plates. Analytical methods for estimating of these forces are presented only for simple plates. For more complex shapes of plates, numerical methods are very helpful. Among a few famous market programs, enabling analysis of MEMS, we can distinguish the program called Comsol Multyphysics which includes a specific module for MEMS. In this paper, the suitability of this program for modelling of simple and more complex plates with perforations in the form of holes will be verified. The tile holes are usually made in order to reduce occurring damping forces. The performed analytical and numerical studies, showed numerous imperfections of the Comsol program which needs to be improved by their programmers.

Źródło:

Biuletyn Wojskowej Akademii Technicznej; 2015, 64, 4; 191-206
1234-5865

Pojawia się w:

Biuletyn Wojskowej Akademii Technicznej

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

Liczby kryterialne w charakterystyce wężownicowego wymiennika ciepła
Criterion numbers in characteristics of a coil heat exchanger

Autorzy:

Smusz, Robert
Wilk, Joanna

Powiązania:

https://bibliotekanauki.pl/articles/194733.pdf

Data publikacji:

2019

Wydawca:

Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza

Tematy:

wężownica
liczba Deana
krytyczna liczba Reynoldsa
coil
Dean number
critical Reynolds number

Opis:

W artykule zaprezentowano przegląd literaturowy oraz analizę porównawczą dotyczącą liczb kryterialnych istotnych w opisie i projektowaniu wężownicowych wymienników ciepła – liczby Deana i krytycznej liczby Reynoldsa. Liczby te uwzględniają specyfikę przepływu płynu w wężownicy powstałej przez nawinięcie rury o przekroju kołowym na walcowej pobocznicy. Omówiono również geometrię wężownicy niezbędną w opisie liczb kryterialnych ze względu na istotny wpływ parametrów geometrycznych na strukturę przepływu. Dokonana analiza porządkuje zakresy stosowalności odpowiednich wzorów kryterialnych w zastosowaniu do opisu zjawisk związanych z intensyfikacją wymiany ciepła w wężownicowym wymienniku, wynikającą z pojawienia się przepływu wtórnego, który jest efektem interakcji siły odśrodkowej, sił bezwładności oraz sił wywołanych lepkością płynu.
The article presents a literature review and a comparative analysis of criterion numbers important in the description and design of coil heat exchangers - the Dean number and the critical Reynolds number. These numbers take into account the specificity of fluid flow in the coil resulting from winding of the circular section pipe on the cylindrical side. Coil geometry necessary in the description of criterion numbers was also discussed due to the significant influence of geometric parameters on the flow structure. The work analyzes the scope of applicability of appropriate criterion formulas in the description of phenomena related to intensification of heat transfer in the coil heat exchanger resulting from the occurrence of secondary flow, which is the effect of interaction of centrifugal forces, inertia forces and forces caused by fluid viscosity.

Źródło:

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika; 2019, z. 91 [299], 1-2; 67-78
0209-2689
2300-5211

Pojawia się w:

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

Pomiar kryzą segmentową strumienia medium dla małych liczb Reynoldsa
Measurement with segmental orifice of flow medium for small Reynolds numbers

Autorzy:

Mrowiec, A.
Kasprzak, D.

Powiązania:

https://bibliotekanauki.pl/articles/267014.pdf

Data publikacji:

2016

Wydawca:

Politechnika Gdańska. Wydział Elektrotechniki i Automatyki

Tematy:

kryza segmentowa
liczba Reynoldsa
współczynnik przepływu
segmental orifice
Reynolds number
flow factor

Opis:

Podstawowym surowcem energetycznym w Polsce jest węgiel. W ostatnich latach podejmowano próby spalania koloidalnych zawiesin pyłu węglowego w oleju napędowym lub opałowym. Przy pomiarach przepływu takich zawiesin, może dochodzić do wytrącania i zalegania w układach przesyłowych osadów, co w efekcie może prowadzić do zaburzeń strumienia przepływu. Wiarygodność pomiaru tego parametru, mogą zapewnić kryzy segmentowe. W artykule zaprezentowano wyniki badań przepływowych kryz segmentowych z przytarczowym punktowym odbiorem ciśnienia różnicowego, przy niewielkich liczbach Reynoldsa oraz symulacje numeryczne dla wybranej kryzy. W badaniach jako medium wykorzystano wodę.
In Poland coal is the main energy resource. As part of the conducted research attempts were made at using suspensoids containing coal dust in gas oil and furnace oil. This leads to a reduction in NOx and SOx percentage without the need for an expensive desulphurization and dust extraction installation. However, there is a need for using cheap but reliable systems to measure the flow of the injected fuel. In real operating conditions various residues may often deposit in fuel transmission systems, which in turn can lead to flow fluctuations. Reliable flow factor measurement requirements can be met by segmental orifices. In the article, based on a research and measurement station, presented were the results of flow measurements with segmental orifices with point reception of differential pressure for small Reynolds numbers as well as numerical simulations. For the selected segmental orifice the flow factor characteristic in the function of the Reynolds number was calculated. In the research, water was used as the medium; the next stage of the research will involve the realization of the proposed solution with the use of hydraulic oil.

Źródło:

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej; 2016, 49; 75-78
1425-5766
2353-1290

Pojawia się w:

Zeszyty Naukowe Wydziału Elektrotechniki i Automatyki Politechniki Gdańskiej

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

Analysis of time-averaged secondary flow cells in wide and narrow straight open channels with lateral bed deformation

Autorzy:

Chattopadhyay, T.
Kundu, S.

Powiązania:

https://bibliotekanauki.pl/articles/38695706.pdf

Data publikacji:

2023

Wydawca:

Instytut Podstawowych Problemów Techniki PAN

Tematy:

turbulent flow
secondary current
method of separation of variable
Reynolds shear stress

Opis:

The usual cellular pattern of the time averaged secondary flow circulation in the central section of wide open channels shows a distorted (laterally or vertically) structure due to the changes in bed configurations along lateral direction. The structures of these secondary circulations (under different bed configurations) are crucial for different types of hydraulic modeling. This study presents mathematical models of the time averaged secondary velocities (lateral and vertical components) for a turbulence-induced secondary current at the central section of a wide open-channel flow under different types of elevated and non-elevated bed conditions. Starting with the Reynolds Averaged Navier-Stokes equation and using the continuity equation, at first the governing equation of secondary flow velocity is obtained including the effects of the eddy viscosity and viscosity of the fluid. The model equations is solved using a separation of the variable technique imposing the bed perturbation condition. Full analytical solutions are achieved through mathematical analysis using suitable boundary conditions consistent with experimental observations. Initially the models are derived for a non-elevated bedforms comprised of alternating equal widths of smooth and rough bed strips. These models are modified further for bedforms with unequal widths of rough and smooth bed strips and elevated periodic bed structures. Four different types of elevated bed configurations are investigated and a general approach is suggested for other types of bed forms. All the proposed models are validated with existing experimental results to ensure the applicability and in each cases, improved results are observed. Obtained results show that the centre of circulation of the cellular structure occurs above the junction of the rough and smooth bed strips (consistent with experimental observations) and it gradually shifts towards the smooth strip, when the length of the rough bed strip is increased. The shifting as a function shows a non-linear pattern with the length of the rough bed strip. A least-square model is proposed to identify the circulation center as a function of the ratio of rough to smooth bed strips. It is also found that the vertically distorted secondary cells are generated when the bed slope strictly increase/decrease throughout the length of the one whole circulation. Finally, all the proposed models are compared with an existing model and an error analysis is done. Results of error analysis show that the present study can be more suitable as it yields improved results.

Źródło:

Archives of Mechanics; 2023, 75, 1-2; 169-211
0373-2029

Pojawia się w:

Archives of Mechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

Flow of viscous incompressible MHD fluid over a suddenly accelerated plate with variable electroconductivity and chemical reaction provoked by radiation

Autorzy:

Ngiangia, Alalibo T.

Powiązania:

https://bibliotekanauki.pl/articles/1191366.pdf

Data publikacji:

2016

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

Chemical reaction
Electrconductivity
Grashof number
MHD
Prandtl number
Radiation
Reynold’s Number

Opis:

A study of a suddenly accelerated plate with variable approximated electronegativity with MHD fluid provoked by chemical reaction and radiation is made. The governing hydrodynamical equations of the physical problem was formulated and its solution and analysis showed that increase in electroconductivity, prandtl number, Reynold’s number, Grashof number, chemical reaction and radiation all result to a corresponding increase in the velocity profile of the fluid while magnetic field increase results to a decrease in the velocity profile of the fluid. The shear stress at the wall of the plate was also determined.

Źródło:

World Scientific News; 2016, 34; 135-145
2392-2192

Pojawia się w:

World Scientific News

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Elastohydrodynamic Contact Model for Calculation of Axial and Angular Stiffness in Thrust Bearing
Elastohydrodynamiczny model kontaktowy do obliczeń sztywności osiowej i kątowej łożysk oporowych

Autorzy:

Temis, M.
Lazarev, A.

Powiązania:

https://bibliotekanauki.pl/articles/140221.pdf

Data publikacji:

2012

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

thrust bearing
elastohydrodynamic contact
Reynolds equation
łożysko oporowe
kontakt elastohydrodynamiczny
równanie Reynoldsa

Opis:

Thrust bearing model is developed for fluid flow calculation and for determination of bearing integral characteristics in the presence of sliding surfaces closure and shaft angular displacements. The model is based on the coupled solution of the problem of incompressible fluid flow between the sliding surfaces and the problem of bearing and shaft elements deformation under the action of the fluid film pressure. Verification of the bearing model results is carried out by the comparison versus the fluid flow calculation results obtained by STAR-CD software and the experimental and theoretical results represented in the certain literature. Thrust bearing characteristics are determined versus sliding surfaces closure and rotating disk (runner) angular displacements. The contribution of the sliding surfaces deformations into bearing integral characteristics is estimated.
Opracowano model łożyska oporowego przeznaczony do obliczeń przepływu płynu i wyznaczania całościowych charakterystyk dla warunków gdy występuje zamknięcie szczeliny między ślizgającymi się powierzchniami i kątowe przemieszczenie wału. Model jest oparty na połączonych rozwiązaniach zagadnienia przepływu nieściśliwego płynu między ślizgającymi się powierzchniami i zagadnienia deformacji elementów łożyska i wału pod wpływem ciśnienia w warstwie płynu. Weryfikacja wyników modelu łożyska jest przeprowadzona przez ich porównanie z wynikami obliczeń przepływu płynu uzyskanymi przy użyciu oprogramowania STAR-CD oraz wynikami eksperymentalnymi i teoretycznymi podawanymi w literaturze. Charakterystyki łożyska ślizgowego są wyznaczone z uwzględnieniem zamknięcia szczeliny smarnej i przemieszczeń kątowych tarczy obrotowej (oporowej). Oszacowano wpływ, jaki mają odkształcenia ślizgających się powierzchni na całościowe charakterystyki łożyska.

Źródło:

Archive of Mechanical Engineering; 2012, LIX, 4; 453-467
0004-0738

Pojawia się w:

Archive of Mechanical Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 26.

Tytuł:

Investigation of swirling flow in diffusers installed at the exit of an axial-flow pump

Autorzy:

Kochevsky, A. N.

Powiązania:

https://bibliotekanauki.pl/articles/1967610.pdf

Data publikacji:

2001

Wydawca:

Politechnika Gdańska

Tematy:

axial flow pump
discharge diffusers
axisymmetrical flow
reduced Reynolds equations
single sweep method

Opis:

The swirling flow in discharge diffusers with a converging rotating hub and diverging casing is modeled by reduced Reynolds equations, and a single sweep method is used for their solution. The flow was probed at the inlet and outlet section of these diffusers under various pump capacities and, therefore, various swirl rates. The correspondence of results in the operating range of the pump was satisfactory concerning the velocity distributions in the outlet section as well as concerning the coefficient of energy losses. The characteristic curves of the pump with different internal angles of discharge diffusers are presented and the optimal internal angle is obtained.

Źródło:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2001, 5, 4; 603-610
1428-6394

Pojawia się w:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 27.

Tytuł:

Modelowanie sił tłumiących występujących w prostych układach MEMS
Modelling of damping forces occuring in simple MEMS systems

Autorzy:

Urbanowicz, K.

Powiązania:

https://bibliotekanauki.pl/articles/208727.pdf

Data publikacji:

2015

Wydawca:

Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego

Tematy:

MEMS
siły tłumiące
równanie Reynoldsa
modelowanie
symulowanie
damping forces
Reynolds equation
modelling
simulation

Opis:

W mikroukładach mechanicznych określanych skrótem MEMS występują pewne siły tłumiące. Na etapie projektowania układów tego typu wartości tych sił muszą zostać dokładnie oszacowane. Jak ukazane zostanie w niniejszej pracy, w układach pracujących z niskimi częstotliwościami najważniejszą siłą będzie siła lepka związana z wypływaniem filmu powietrznego spod pracujących płytek układów. Siłę tę można z dużą dokładnością szacować metodami analitycznymi znanymi z literatury. Wponiższej pracy ukazane zostaną znane rozwiązania analityczne stosowane często w praktyce dla prostych płytek. Wykonane zostaną również proste symulacje zarówno z wykorzystaniem opisanych rozwiązań analitycznych, jak i z użyciem specjalistycznego programu o nazwie Comsol Multiphysics. Przeprowadzone badania analityczno-numeryczne wykażą skuteczność oprogramowania numerycznego.
A certain damping force occurs in the micro-mechanical systems referred as MEMS. At the design stage of such systems, these forces must be accurately estimated. As shown in this work, in all systems operating at low frequencies, most important force is the one associated with the flotation of air film from the volume between two parallel operating movable MEMS plates. This force can be accurately estimated by analytical methods known from the literature. The paper presents analytical solutions that are frequently used in practice for simple plates. Also some simple simulations, using all described analytical solutions compared with the results of specialized program called Comsol Multyphysics, are shown. Presented research demonstrate the effectiveness of numerical software.

Źródło:

Biuletyn Wojskowej Akademii Technicznej; 2015, 64, 4; 165-189
1234-5865

Pojawia się w:

Biuletyn Wojskowej Akademii Technicznej

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 28.

Tytuł:

Analysis of selected aspects of a tank gassing-up process on board liquefied petroleum gas carrier. Part I

Autorzy:

Wieczorek, Agnieszka

Powiązania:

https://bibliotekanauki.pl/articles/1845464.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

convective heat transfer
Reynolds number
nanofluid
single
wall
carbon
nanotube
SWCNT
laminar flow

Opis:

The paper is a thermodynamics analysis of the removal of any inert gas from the tank using the vapors of any liquefied petroleum gas cargo (called cargo tank gassing-up operation). For this purpose, a thermodynamic model was created which considers two boundary cases of this process. The first is a ‘piston pushing’ of inert gas using liquefied petroleum gas vapour. The second case is complete mixing of both gases and removal the mixture from the tank to the atmosphere until desired concentration or amount of liquefied petroleum gas cargo in the tank is reached. Calculations make it possible to determine the amount of a gas used to complete the operation and its loss incurred as a result of total mixing of both gases.

Źródło:

Archives of Thermodynamics; 2021, 42, 2; 43-58
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

Numerical investigation of convective heat transfer of single wall carbon nanotube nanofluid laminar flow inside a circular tube

Autorzy:

Saeed, Farqad Rasheed
Jasim, Marwah A.
Mahmood, Natheer B.
Jaffar, Zahraa M.

Powiązania:

https://bibliotekanauki.pl/articles/1845470.pdf

Data publikacji:

2021

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

convective heat transfer
reynolds number
nanofluid
single
wall
carbon
nanotube
SWCNT
laminar flow

Opis:

This study presents the behavior of a single wall carbon nanotube (SWCNT)/water nanofluid for convective laminar flow inside a straight circular pipe heated by a constant heat flux. Five volume fractions of SWCNT were used to investigate their effect on the heat transfer coefficient, Nusselt number, temperature distribution and velocity field in comparison with pure water flow. One model for each property was tested to calculate the effective thermal conductivity, effective dynamic viscosity, and effective specific heat of the SWCNT/water mixture. The models were extracted from experimental data of a previous work. The outcomes indicate that the rheological behavior of SWCNT introduces a special effect on the SWCNT/water properties, which vary with SWCNT volume fraction. The results show an improvement in the heat transfer coefficient with increasing volume fraction of nanoparticles. The velocity of SWCNT/water nanofluid increased by adding SWCNT nanoparticles, and the maximum increase was registered at 0.05% SWCNT volume fraction. The mixture temperature is increased with the axial distance of the pipe but a reduction in temperature distribution is observed with the increasing SWCNT volume fraction, which reflects the effect of thermophysical properties of the mixture.

Źródło:

Archives of Thermodynamics; 2021, 42, 2; 103-119
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 30.

Tytuł:

Numerical investigation and sensitivity analysis of turbulent heat transfer and pressure drop of Al2O3/H2O nanofluid in straight pipe using response surface methodology

Autorzy:

Fadodun, Olatomide G.
Amosun, Adebimpe A.
Salau, Ayodeji O.
Olaloye, David O.
Ogundeji, Johnson A.
Ibitoye, Francis I.
Balogun, Fatai A.

Powiązania:

https://bibliotekanauki.pl/articles/239962.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

nusselt number
Reynolds number
pressure drop
response surface methodology
nanofluid
single phase flow

Opis:

In this paper, investigation of the effect of Reynolds number, nanoparticle volume ratio, nanoparticle diameter and entrance temperature on the convective heat transfer and pressure drop of Al2O3/H2O nanofluid in turbulent flow through a straight pipe was carried out. The study employed a computational fluid dynamic approach using single-phase model and response surface methodology for the design of experiment. The Reynolds average Navier-Stokes equations and energy equation were solved using k-ε turbulent model. The central composite design method was used for the response-surface-methodology. Based on the number of variables and levels, the condition of 30 runs was defined and 30 simulations were performed. New models to evaluate the mean Nusselt number and pressure drop were obtained. Also, the result showed that all the four input variables are statistically significant to the pressure drop while three out of them are significant to the Nusslet number. Furthermore, sensitivity analysis carried out showed that the Reynolds number and volume fraction have a positive sensitivity to both the mean Nusselt number, and pressure drop, while the entrance temperature has negative sensitivities to both.

Źródło:

Archives of Thermodynamics; 2020, 41, 1; 3-30
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 31.

Tytuł:

A turbulent heat flux two-equation $Θ^2 - ε_Θ$ closure based on the V2F turbulence model

Autorzy:

Karcz, M.
Badur, J.

Powiązania:

https://bibliotekanauki.pl/articles/2028986.pdf

Data publikacji:

2003

Wydawca:

Politechnika Gdańska

Tematy:

turbulent heat transfer
turbulent Prandtl number
Durbin's model of turbulence
low Reynolds number models

Opis:

The paper deals with the proposition of a two-equation turbulent heat flux closure without any damping function. The model has been based on Durbin's V2F dynamic turbulence closure and the Deng-Wu-Xi thermal turbulence model. Both models have been implemented into the FLUENT code by a User Defined Function. Results of numerical computation have been compared with experimental data for developing a thermal field in a pipe by Nagano and DNS heat transfer prediction for a two-dimensional channel flow by Kasagi.

Źródło:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2003, 7, 3; 375-387
1428-6394

Pojawia się w:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

Noise radiation from circular rods at low-moderate Reynolds number

Autorzy:

Kopania, Joanna Maria
Bogusławski, Grzegorz
Gaj, Patryk
Wójciak, Kamil

Powiązania:

https://bibliotekanauki.pl/articles/128113.pdf

Data publikacji:

2019

Wydawca:

Politechnika Poznańska. Instytut Mechaniki Stosowanej

Tematy:

aeroacoustic noise
circular rod
low Reynolds number
hałas aeroakustyczny
pręt kołowy
niska liczba Reynoldsa

Opis:

The well-known dominant sources of airframe noise are associated with unsteadiness of separated and/or vortical flow regions around the high-lift system (flaps, slats) and the aircraft undercarriage (landing gear). Current practical landing gear noise prediction models are individual component - based, which means that the various components are divided into groups according to the frequency range, in which they predominantly radiate noise. Since the far-field noise spectra are approximately Strouhal - based, the emitted frequency is assumed to be directly related to their size: the large elements are responsible for the low frequency region of the spectra, and the small components for the high frequency region. On the basis of such understanding of the noise generation mechanism, the special configurations that lead to considerable noise suppression were proposed. One element of these configurations are rods with different shape and cross section. In this work the situation when circular rods are in area of laminar-turbulent flow were analysed. The measurements were carried out for single circular rod with different diameters to study the noise effect depended on Reynolds number. Far field noise for broad range of Reynolds numbers was also examined depending on distance from the source of noise.

Źródło:

Vibrations in Physical Systems; 2019, 30, 1; 1-8
0860-6897

Pojawia się w:

Vibrations in Physical Systems

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

Influence of total inertia effects in a thrust curvilinear bearing lubricated with Newtonian lubricants

Autorzy:

Walicka, A.
Jurczak, P.

Powiązania:

https://bibliotekanauki.pl/articles/265900.pdf

Data publikacji:

2017

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

inertia
modified Reynolds equation
pressure distribution
load-capacity
bezwładność
równanie Reynoldsa
rozkład ciśnienia
nośność

Opis:

In the paper, the flow of a Newtonian type of lubricant in the clearance of a curvilinear bearing is considered. It is assumed that the bearing walls are modelled as smooth and impermeable. In analytical considerations, full inertia of the longitudinal flow and partial inertia of the circumferential flow are taken into account. The equation of motion of the lubricant is solved by the modified method of averaged inertia. A thrust bearing and spherical bearing are considered, for which dimensionless pressure distributions and the bearing capacity are given.

Źródło:

International Journal of Applied Mechanics and Engineering; 2017, 22, 4; 1045-1058
1734-4492
2353-9003

Pojawia się w:

International Journal of Applied Mechanics and Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 34.

Tytuł:

Experimental and numerical determination of the hydrodynamic coefficients of an autonomous underwater vehicle

Autorzy:

Sakaki, Abdollah
Kerdabadi, Mohsen Sadeghian

Powiązania:

https://bibliotekanauki.pl/articles/135543.pdf

Data publikacji:

2020

Wydawca:

Akademia Morska w Szczecinie. Wydawnictwo AMSz

Tematy:

Reynolds averaged Navier–Stokes
computational fluid dynamics
linear coefficients
non-linear coefficients
underwater vehicle

Opis:

Computational fluid dynamics (CFD) has progressed rapidly in the past fifty years and is now used in many industrial fields, such as air, space, and marine engineering. CFD has an irreplaceable role in marine design and scientific research, and its applications within this field continue to grow with the development of computers. CFD is used to quickly and inexpensively simulate fluid behaviour using the Reynolds Averaged Navier–Stokes (RANS) equations to calculate hydrodynamic coefficients, which are needed in manoeuvrability studies of underwater vehicles (UWV). Here, these computations are performed for six geometrical shapes that represent typical autonomous underwater vehicles (AUVs) currently in use. Resistance test simulations at up to 20o drift angles were conducted for AUVs with different length-to-diameter ratios. The results were compared with the experimental data and current quasi-experimental relationships, which suggested that the CFD predictions were adequately precise and accurate. These predictions indicated that there was a non-linear relationship between forces and moments and the lateral speed. Moreover, both linear and non-linear hydrodynamic coefficients were calculated.

Źródło:

Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2020, 62 (134); 124-135
1733-8670
2392-0378

Pojawia się w:

Zeszyty Naukowe Akademii Morskiej w Szczecinie

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Heat transfer and friction characteristics in three-side solar air heaters with the combination of multi-v and transverse wire roughness

Autorzy:

Kumar, Dhananjay

Powiązania:

https://bibliotekanauki.pl/articles/2204071.pdf

Data publikacji:

2023

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

absorber plate
fluid flow
heat transfer
solar air heater
reynolds number
relative roughness height

Opis:

The present paper describes the experimental analysis of heat transfer and friction factor for glass protected three-side artificially roughened rectangular duct solar air heaters (SAHs) having an arrangement of multiple-v and transverse wires (top wall multi-v and two side walls transverse) under the absorber plate, and compares their performance with that of one-side roughened solar air heaters under similar operating conditions. The investigated three-side solar air heaters are characterized by a larger rate of heat transfer and friction factor as compared to one-side artificially roughened SAHs by 24–76% and 4–36%, respectively, for the identical operating parameters. The air temperature below the three-side rugged duct is by 34.6% higher than that of the one-side roughened duct. Three-side solar air heaters are superior as compared to one-side artificially roughened solar air heaters qualitatively and quantitatively both.

Źródło:

Archives of Thermodynamics; 2023, 44, 1; 63--87
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 36.

Tytuł:

The analysis of oil balance in crank bearing
Analiza bilansu oleju w łożysku korbowym

Autorzy:

Kyureghyan, K.
Piekarski, W.

Powiązania:

https://bibliotekanauki.pl/articles/792161.pdf

Data publikacji:

2014

Wydawca:

Komisja Motoryzacji i Energetyki Rolnictwa

Tematy:

hydrodynamic lubrication
cross slide bearing
Reynolds equation
oil balance
crank bearing
analysis
signal parameter

Źródło:

Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2014, 14, 4
1641-7739

Pojawia się w:

Teka Komisji Motoryzacji i Energetyki Rolnictwa

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 37.

Tytuł:

Two-dimensional vertical analysis of dam-break flow

Autorzy:

Zima, P.

Powiązania:

https://bibliotekanauki.pl/articles/1933149.pdf

Data publikacji:

2007

Wydawca:

Politechnika Gdańska

Tematy:

mathematical modeling
Reynolds-averaged Navier-Stokes equations
rapidly varied free surface flow
dam-break flow

Opis:

The paper concerns mathematical modeling of free surface open-channel water flow. Two-dimensional vertical Reynolds-averaged Navier-Stokes equations were used to simulate the flow. They were solved with the SIMPLE algorithm of the finite difference method using the Marker and Cell technique to trace free surface movement. The dam-break flow (water column collapse) problem on a horizontal and frictionless bottom was investigated as a test case. The mechanics of dam-break flow for wet and dry bed conditions was analyzed on the basis of numerical simulations. The obtained results are shown for varying head of water in the downstream channel. The possibility of using the shallow-water equations and the RANS model to simulate rapidly varied flows is discussed.

Źródło:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2007, 11, 4; 315-328
1428-6394

Pojawia się w:

TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

Computational model of high altitude aircraft aerodynamics

Autorzy:

Zalewski, W.

Powiązania:

https://bibliotekanauki.pl/articles/242754.pdf

Data publikacji:

2016

Wydawca:

Instytut Techniczny Wojsk Lotniczych

Tematy:

transport
air transport
simulation
propeller-driven unmanned airplane
propeller-wing interaction
low Reynolds number flows

Opis:

The paper presents computational fluid dynamics hybrid model for analysis of complex flow composed of flow zones at low Reynolds number and flow zones at relatively high Reynolds number conditions. In the described model both ranges of the flow are separated and resolved independently using different way of simulation. That kind of phenomenon is typical for aerodynamics of unmanned propeller driven aircrafts operating at very high altitude conditions (stratospheric). That type of aerial vehicles is now used for military and scientific purposes. In many cases, the wings of a plane are operating at relatively high Reynolds number flow conditions and low angles of attack while the parts of the propeller blades are working at low Reynolds number flow condition and high angles of attack. Described numerical model was used for analysis of the impact of working propellers on the aerodynamics of the aircraft. Analysis was made on the example of a twin-engine, unmanned aircraft with electric motors during the high altitude flight. Three configurations were studied and compared: the plane without propellers, the plane with pusher propellers and the plane with tractor propellers. For each configuration, distributions of aerodynamic coefficients along the span of the wing and their global values for the entire aircraft were estimated. Calculations were performed using the Fluent solver with implementation of a model of propeller based on the Blade Element Theory. Results of the analysis indicate a slight advantage of the tractor propellers configuration.

Źródło:

Journal of KONES; 2016, 23, 1; 437-444
1231-4005
2354-0133

Pojawia się w:

Journal of KONES

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

Zmiana ciśnienia w poprzecznym łożysku ślizgowym przy laminarnym niestacjonarnym smarowaniu
Variation of Pressure in a Slide Journal Bearing with Laminar Unsteady Lubrication

Autorzy:

Krasowski, P.

Powiązania:

https://bibliotekanauki.pl/articles/359411.pdf

Data publikacji:

2006

Wydawca:

Akademia Morska w Szczecinie. Wydawnictwo AMSz

Tematy:

łożyska ślizgowe
EXPLO-SHIP 2006
równanie Reynoldsa
rozkład ciśnienia
journal bearing
Reynolds equation
pressure distribution

Opis:

W artykule przedstawiono przykład rozwiązania numerycznego zmodyfikowanego równania Reynoldsa dla laminarnego niestacjonarnego smarowania poprzecznego cylindrycznego łożyska ślizgowego. Przyjęto izotermiczny model łożyska o nieskończonej długości, smarowanego olejem o własnościach newtonowskich i lepkości dynamicznej zależnej od ciśnienia. Wyznaczono rozkłady ciśnienia hydrodynamicznego w łożysku przy zaburzeniach prędkości przepływu oleju w kierunku obwodowym na czopie i na panewce.
This paper presents the results of numerical solutions modified by the Reynolds equation of laminar unsteady lubrication of a cylindrical slide journal bearing. The particular solutions are limited to isothermal models of bearing with infinite length, lubricated by Newtonian oil with the dynamic viscosity dependent on pressure. The disturbances are related with unsteady velocity of oil flow on the sleeve and on the journal. The results are shown in the diagram of hydrodynamic pressure in the dimensionless form in time intervals of displacement duration.

Źródło:

Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2006, 10 (82); 287-298
1733-8670
2392-0378

Pojawia się w:

Zeszyty Naukowe Akademii Morskiej w Szczecinie

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

The influence of oil’s exploitation time on load carrying capacity in a slider bearing

Autorzy:

Sikora, G.
Miszczak, A.

Powiązania:

https://bibliotekanauki.pl/articles/244279.pdf

Data publikacji:

2015

Wydawca:

Instytut Techniczny Wojsk Lotniczych

Tematy:

oil ageing
numerical calculations
Reynolds equation
pressure distribution
load carrying capacities
viscosity changes in time

Opis:

In this paper, authors are presenting conclusions of the numerical calculations of pressure distribution and capacity in a slider bearing with taking changes of oil viscosity in exploitation time into account. Changes of the engine oil’s viscosity, which depend on the exploitation time, were determined on Haake Mars III rheometer and the conclusions were published in Solid State Phenomena and Logistyka in 2015. Numerical calculations were performed by solving of Reynolds equation, using finite difference method and own calculation procedures in Mathcad 15. Reynolds equation was developed by solving the continuity equation and the momentum conservation equation from the fundamentals. For the considerations, the laminar and stationary lubricating of the slider bearing of finite length and full angle of wrap were taken. Assumption of the stationary flow concerns lack of changes in flow parameters in short period of considered phenomena, f. ex. in one hour. Smooth and non-porous bushing were assumed. The aim of this paper was preliminary estimation of influence of viscosity changes in the exploitation time on the load carrying capacities of the cross slider bearing. Wherefore, the viscosity changes dependence on the pressure, temperature and also shear rate, were not taken into account. The basic equations were developed to the non-dimensional form and estimated according to the thin layer theory. In the calculations, the Reynolds boundary conditions concerning pressure distribution were taken into account. Preliminary calculations were performed for different models of viscosity changes in time and circumstances, where the viscosity increases and decreases in exploitation time.

Źródło:

Journal of KONES; 2015, 22, 3; 207-212
1231-4005
2354-0133

Pojawia się w:

Journal of KONES

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Effect of relative velocity between rough surfaces: hydrodynamic lubrication of rotary lip seal

Autorzy:

Lahjouji, I.
El Gadari, M.
El Fahime, B.
Radouani, M.

Powiązania:

https://bibliotekanauki.pl/articles/264554.pdf

Data publikacji:

2017

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

hydrodynamic lubrication
roughness
relative velocity
Reynolds equation
finite differences
smarowanie
chropowatość
prędkość względna
równanie Reynoldsa

Opis:

Since the sixties, most of numerical studies that model the rotary lip seal lubrication have been restricted by assuming that one of the two opposing surfaces is smooth: either the lip or the shaft. This hypothesis, although it is verified only for a shaft roughness ten times smaller than that of the seal, is the best solution to avoid the transient term “∂h/∂t” in the deterministic approach. Thus, the subject of the present study is twofold. The first part validates the current hydrodynamic model with the international literature by assuming the asperities on the lip and shaft as a two-dimensional cosine function. In the second part the Reynolds equation for rough surfaces with relative motion is solved. The numerical results show that the relative motion between rough surfaces impacts significantly the load support and the leakage rate, but affects slightly the friction torque.

Źródło:

International Journal of Applied Mechanics and Engineering; 2017, 22, 2; 321-332
1734-4492
2353-9003

Pojawia się w:

International Journal of Applied Mechanics and Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 42.

Tytuł:

Exergy based analysis of solar air heater duct with W-shaped rib roughness on the absorber plate

Autorzy:

Patel, Sumer Singh
Lanjewar, Atul

Powiązania:

https://bibliotekanauki.pl/articles/240081.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

solar air heater
W-shape rib
exergetic efficiency
Reynolds number
thermal efficiency
temperature rise parameter

Opis:

Exergy analysis is a powerful thermodynamic tool and it helps in computing the actual output of a system. It helps the researchers to optimize the roughened solar air heater design to compensate the present and also the future needs. In this study, investigation on exergetic performance evaluation of a solar air heater with W-shaped roughened absorber surface analytically by employing mathematical model and the results obtained are compared with smooth plate solar air heater under same operating conditions. The exergetic efficiency curves has been plotted as a function of different values of Reynolds number and temperature rise parameter for different roughness parameters. The maximum augmentation in the exergetic efficiency of the solar air heater with W-shaped roughened surface as compared to solar air heater with smooth surface has been obtained as 51% corresponding to the relative roughness height of 0.03375 and the rib angle of attack about 60°. Based on the exergetic efficiency the suitable design parameters of solar air heater with W-shaped roughened are determined.

Źródło:

Archives of Thermodynamics; 2019, 40, 4; 21-48
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 43.

Tytuł:

On the Reynolds transport theorem for three phase systems with storage in interfaces

Autorzy:

Skiepko, T.

Powiązania:

https://bibliotekanauki.pl/articles/239942.pdf

Data publikacji:

2011

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

transportowy teoremat Reynoldsa
trójfaza
zasób na granicy rozdziału faz
interface storage
Reynolds transport theorem
three phases

Opis:

In the paper, the Reynolds transport theorem (RTT) for three phase systems is developed, in terms associated with a moving control volume. The basic tools applied to the derivation are the generalized transport theorem by Truesdell and Toupin, and generalized surface transport theorem by Aris as well as Slattery. The final results referenced to a generic extensive quantity demonstrate the theorem in the integral instantaneous from. As a further illustration of applicability of the theorem relation developed some specific forms are deduced from such as for multiphase systems in terms of fixed control volume, surface systems and homogeneous spatial systems.

Źródło:

Archives of Thermodynamics; 2011, 32, 1; 21-44
1231-0956
2083-6023

Pojawia się w:

Archives of Thermodynamics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

Numerical investigations of pulsatile flow in stenosed artery

Autorzy:

Bit, A.
Chattopadhyay, H.

Powiązania:

https://bibliotekanauki.pl/articles/306672.pdf

Data publikacji:

2014

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

płyn nienewtonowski
przepływ pulsacyjny
liczby Reynoldsa
non-Newtonian
pulsatile
hemodynamic
stenoses
Reynolds number
oscillatory shear index

Opis:

Purpose: Abnormalities in blood vessels by virtue of complex blood flow dynamics is being supported by non-Newtonian behavior of blood. Thus it becomes a focus of research to most of the researchers. Additionally, consideration of real life patient specific model of vessel as well as patient specific inlet flow boundary condition implementation was limited in literature. Thus a thorough implementation of these considerations was done here.Method: In this work, a numerical investigation of hemodynamic flow in stenosed artery has been carried out with realistic pulsating profile at the inlet. Flow has been considered to be laminar due to arresting condition of cardiovascular state of the subject. Two non-Newtonian rheological models namely, Power Law viscosity model and Quemada viscosity model have been used. Two different patient-specific pulsatile profiles are considered at the inlet of a long stenosed artery with varying degree of stenoses from 25% to 80%. Results: Transient form of Navier-Stokes equation is solved in an axi-symmetric domain to calculate the detailed flow structure of the flow field. From the simulation data, temporal and time averaged wall shear stress, oscillatory shear index and pressure drop are calculated. Conclusions: The results demonstrate that oscillatory shear index and wall shear stresses areextensively governed by the degree of stenoses. The position and movement of recirculation bubbles are found to vary with flow Reynolds number.

Źródło:

Acta of Bioengineering and Biomechanics; 2014, 16, 4; 33-44
1509-409X
2450-6303

Pojawia się w:

Acta of Bioengineering and Biomechanics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 45.

Tytuł:

The search of spatial functions of pressure in adjustable hydrostaticradial bearing

Autorzy:

Fedorynenko, D.
Boyko, S.
Sapon, S.

Powiązania:

https://bibliotekanauki.pl/articles/387485.pdf

Data publikacji:

2015

Wydawca:

Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej

Tematy:

hydrostatic bearing
lubricating film
spatial functions
hydromechanics
Reynold’s equation
łożyska hydrostatyczne
smarowanie
hydromechanika
równanie Reynoldsa

Opis:

The analysis of spatial functions of pressure considering the geometrical deviations and the elastic deformation of conjugate surace have been considered. The analysis of spatial functions of pressure is performed by the finite element method. The difference of the size of pressure in a tangential direction of a pocket of a support under various service conditions has been investigated. A recommendation for improving of operational characteristics in regulated hydrostatic radial bearing has been developed.

Źródło:

Acta Mechanica et Automatica; 2015, 9, 1; 23-26
1898-4088
2300-5319

Pojawia się w:

Acta Mechanica et Automatica

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 46.

Tytuł:

Hydrodynamika w mieszalniku z mieszadłem ze zwiniętymi śrubowo łopatkami wstęgowymi
Hydrodynamics in a tank equipped with the impeller with helically rolled ribbon blades

Autorzy:

Stelmach, J.
Rieger, F.
Jirout, J.

Powiązania:

https://bibliotekanauki.pl/articles/2073321.pdf

Data publikacji:

2018

Wydawca:

Stowarzyszenie Inżynierów i Techników Mechaników Polskich

Tematy:

mieszalnik
zwinięte śrubowo łopatki wstęgowe
hydrodynamika
naprężenie Reynoldsa
mixer
helically rolled ribbon blades
hydrodynamics
Reynolds stresses

Opis:

Przedstawiono wyniki pomiarów prędkości i naprężeń Reynoldsa dla mieszadła ze zwiniętymi śrubowo łopatkami wstęgowymi. Mieszadło tego typu wytwarza obwodową cyrkulację cieczy w mieszalniku. Zainstalowanie przegród w zbiorniku w znaczącym stopniu wpływa na osiowy przepływ cieczy. Maksymalne wartości naprężeń Reynoldsa dla tego typu mieszadła są porównywalne z takimi naprężeniami generowanymi przez turbinę Rushtona.
The paper presents measurement results of velocity and Reynolds stresses for an impeller with helically rolled ribbon blades. The impeller of this type generates tangential circulation of liquid in the tank. The baffles mounted in a tank significantly affect the axial flow of liquid. The maximum values of Reynolds stresses for this type of impeller are comparable to those of the Rushton turbine.

Źródło:

Inżynieria i Aparatura Chemiczna; 2018, 5; 152--153
0368-0827

Pojawia się w:

Inżynieria i Aparatura Chemiczna

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 47.

Tytuł:

Mechanical parameters of the curvilinear squeeze film bearing lubricated by a Gecim-Winer fluid

Autorzy:

Walicka, A.
Walicki, E.

Powiązania:

https://bibliotekanauki.pl/articles/265583.pdf

Data publikacji:

2017

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

modified Reynolds equation
squeeze film
mechanical parameters of bearing
additives
równanie Reynoldsa
łożysko ślizgowe
równanie ruchu

Opis:

Based upon a Gecim-Winer fluid flow model, a curvilinear squeeze film bearing is considered. The equations of motion are given in a specific coordinates system. After general considerations on the Gecim-Winer fluid flow these equations are used to derive the Reynolds equation. The solution of this equation is obtained by a method of successive approximation. As a result one obtains formulae expressing the pressure distribution and load-carrying capacity. The numerical examples of the Gecim-Winer fluid flow in gaps of two simple bearings: radial and spherical are presented.

Źródło:

International Journal of Applied Mechanics and Engineering; 2017, 22, 2; 465-473
1734-4492
2353-9003

Pojawia się w:

International Journal of Applied Mechanics and Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 48.

Tytuł:

Curvilinear squeeze film bearing lubricated with a DeHaven fluid or with similar fluids

Autorzy:

Walicka, A.
Jurczak, P.
Falicki, J.

Powiązania:

https://bibliotekanauki.pl/articles/264447.pdf

Data publikacji:

2017

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

DeHaven fluid
modified Reynolds equation
squeeze film
mechanical parameters of the bearing
łożysko
równanie Reynoldsa
płyn nienewtonowski

Opis:

In the paper, the model of a DeHaven fluid and some other models of non-Newtonian fluids, in which the shear strain rates are known functions of the powers of shear stresses, are considered. It was demonstrated that these models for small values of material constants can be presented in a form similar to the form of a DeHaven fluid. This common form, called a unified model of the DeHaven fluid, was used to consider a curvilinear squeeze film bearing. The equations of motion of the unified model, given in a specific coordinate system are used to derive the Reynolds equation. The solution to the Reynolds equation is obtained by a method of successive approximations. As a result one obtains formulae expressing the pressure distribution and load-carrying capacity. The numerical examples of flows of the unified DeHaven fluid in gaps of two simple squeeze film bearings are presented.

Źródło:

International Journal of Applied Mechanics and Engineering; 2017, 22, 3; 697-715
1734-4492
2353-9003

Pojawia się w:

International Journal of Applied Mechanics and Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 49.

Tytuł:

Pressure distribution in a squeeze film spherical bearing with rough surfaces lubricated by an ellis fluid

Autorzy:

Jurczak, P.
Falicki, J.

Powiązania:

https://bibliotekanauki.pl/articles/265779.pdf

Data publikacji:

2016

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

łożyska
równanie Reynoldsa
model plastyczny
pseudo-plastic model of Ellis fluid
thrust curvilinear bearings
modified Reynolds equation

Opis:

In this paper, the solution to a problem of pressure distribution in a curvilinear squeeze film spherical bearing is considered. The equations of motion of an Ellis pseudo-plastic fluid are presented. Using Christensen’s stochastic model of rough surfaces, different forms of Reynolds equation for various types of surface roughness pattern are obtained. The analytical solutions of these equations for the cases of externally pressurized bearing and squeeze film bearing are presented. Analytical solutions for the film pressure are found for the longitudinal and circumferential roughness patterns. As a result the formulae expressing pressure distribution in the clearance of bearing lubricated by an Ellis fluid was obtained. The numerical considerations for a spherical bearing are given in detail.

Źródło:

International Journal of Applied Mechanics and Engineering; 2016, 21, 3; 593-610
1734-4492
2353-9003

Pojawia się w:

International Journal of Applied Mechanics and Engineering

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:

Thermal performance of corrugated plate heat exchanger using ethylene glycol as test fluid

Autorzy:

Sreedhar Rao, Battula
Keerthana Reddy, Chittireddy
Meena, Pullurwar
Kishore Kumar, Sriramoju

Powiązania:

https://bibliotekanauki.pl/articles/1819182.pdf

Data publikacji:

2020

Wydawca:

Politechnika Koszalińska. Wydawnictwo Uczelniane

Tematy:

corrugated plate heat exchanger
overall heat transfer coefficient
effectiveness
Reynolds number
współczynnik przenikania ciepła
efektywność
liczba Reynoldsa

Opis:

This paper reports an experimental comparative thermal analysis of a flat plate heat exchanger and corrugated plate heat exchanger (CPHE) of different corrugation angles using ethylene glycol as test fluid. The experiments were carried out in counter current mode using water as hot fluid at 75°C. Design of each plate provided with eleven thermocouple sensors to determine the temperatures, in which seven were used to measure the surface temperature of plate and four were used to measure the inlet and outlet bulk temperature of cold and hot fluids. The mass flow rate of test fluid, varied between 0.5 to 4 liters per minute and corresponding steady state temperatures is measured. Using experimental readings, temperature difference between the inlet and outlet streams (∆T), logarithmic mean temperature difference (LMTD) and overall heat transfer coefficient (U) are determined. The obtained ∆T and U values of corrugation angles (30°, 50°) of CPHE were compared with those of flat plate heat exchangers. For corrugation angle of 30° and 50°, the ∆T and U values increases with increase of mass flow rate of the fluid. The turbulence in the flow increases due to increase in the corrugation angle, which results in the enhancement of heat transfer. Moreover, thermal effectiveness (ε) is estimated using NTU method and compared for all the plates. As the NRe values gradually increases, ε decreases for flat plate and CPHE (θ = 30° and θ= 50°). At low NRe value of 114, observed a maximum ε (≅0.998) value for corrugated angle of 50°. There is adequate contact time between the cold and hot fluids at low Reynolds number, so maximum rate of heat transfer is possible, as a result ε values are high.

Źródło:

Journal of Mechanical and Energy Engineering; 2020, 4, 2; 167--172
2544-0780
2544-1671

Pojawia się w:

Journal of Mechanical and Energy Engineering

Dostawca treści:

Biblioteka Nauki

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