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Tytuł:
A systematic analysis of the friction losses on bearings of modern turbocharger
Autorzy:
Vanhaelst, R.
Kheir, A.
Czajka, J.
Powiązania:
https://bibliotekanauki.pl/articles/134027.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
friction power
test rig
turbocharger
floating bearing
ball bearing
oil temperature
oil pressure
thrust force
moc tarcia
stanowisko badawcze
turbosprężarka
łożysko swobodne
łożysko kulkowe
temperatura oleju
ciśnienie oleju
siła odporu
Opis:
In the article, a novel test rig for determining the friction losses of modern turbocharger is presented. The friction torque of the bearing of turbocharger can be measured direct and stationary at any speed up to 100,000 min–1 by the friction test rig developed by the Ostfalia, University of Applied Science (UAS). Since 2010, over 50 turbochargers were measured on the test bench in extensive measurement series. The results give valuable and new insights of the influence of the next parameters on the bearing friction losses: oil temperature, oil pressure, thrust force and oil flow rate. Furthermore, a comparison between the different bearing types (semi-floating, full floating and ball bearings) was performed. The main observations and results are discussed in the scientific article.
Źródło:
Combustion Engines; 2016, 55, 1; 22-31
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adhesion influence on the oil velocity and friction forces in hyperbolic microbearing gap
Autorzy:
Wierzcholski, K.
Miszczak, A.
Powiązania:
https://bibliotekanauki.pl/articles/247611.pdf
Data publikacji:
2010
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
adhesion forces
hyperbolic micro-bearing
oil velocity
hydrodynamic pressure
Opis:
In this paper are presented the influences of the adhesion forces occurring in hyperbolic micro contact on the oil velocity and friction forces in hyperbolic micro bearing gap. Here are elaborated the dependences between adhesive forces and oil dynamic viscosity in super thin boundary layer and influences of adhesive forces on the oil velocities and friction forces in micro- and nano-scale arising between two cooperating hyperbolic surfaces in micro-bearings. Oil dynamic viscosity is a sum of classical viscosity and viscosity caused by adhesion and cohesion forces. In hyperbolic micro-bearing the influence of adhesive forces on friction forces is visible not only in friction forces caused by the hydrodynamic pressure but also in friction forces caused by the oil flow velocity. The pressure distributions and capacity values in machine hyperbolic slide micro-bearings are determined in the lubrication region which is defined on the micro-bearing surfaces. Numerical calculations are performed in Mathcad 14 Professional Program implemented by virtue of difference method. In this paper are derived the formulas for velocity components, pressure distributions, friction forces and friction coefficients in hyperbolic coordinates and at the same time the adhesion forces are considered. Up to now the influence of adhesion forces on oil velocity and friction force changes in hyperbolic micro-bearing gap were not considered in analytical way. Present paper elaborat es the preliminary assumptions of hydrodynamic theory of lubrication for hyperbolic micro-bearing in the case if during the lubrication the adhesion forces are taken into account.
Źródło:
Journal of KONES; 2010, 17, 3; 483-489
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Analysis of Hydrodynamic Pressure Distribution and Load Carrying Capacity of a Conical Slide Bearing Lubricated with Non-Newtonian Second Grade Flui
Analiza rozkładu ciśnienia hydrodynamicznego i siły nośnej w stożkowym łożysku ślizgowym smarowanym olejem o właściwościach nienewtonowskich drugiego rzędu
Autorzy:
Miszczak, Andrzej
Czaban, Adam
Powiązania:
https://bibliotekanauki.pl/articles/189591.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
small parameter method
Reynolds type equation
load carrying capacity
hydrodynamic pressure
Rivlin-Ericksen model
non-Newtonian oil
conical slide bearing
metoda małego parametru
równanie typu Reynoldsa
siła nośna
ciśnienie hydrodynamiczne
model Rivlina-Ericksena
olej o właściwościach nienewtonowskich
stożkowe łożysko ślizgowe
Opis:
In this paper, the authors present the equations of the hydrodynamic lubrication theory for conical slide bearings lubricated with the oil with properties described by the Rivlin-Ericksen model. It is assumed, that the considered lubricating oil shows non-Newtonian properties, i.e. it is an oil for which, apart from the classic dependence of oil viscosity on pressure, temperature and operating time, there is also a change in dynamic viscosity values caused by the changes of shear rate. The method of a small parameter was used to solve the conservation of momentum, stream continuity, and energy conservation equations. The small parameter method consists in presenting the sought functions (pressure, temperature, components of the velocity vector) in the form of a uniformly convergent series expansion in powers of a constant small parameter. These functions are substituted into the system of basic equations, and then the series are multiplied by the Cauchy method. By a comparison of the coefficients with the same powers of a small parameter, we obtain systems of partial differential equations, from which the subsequent approximations of unknowns of the sought functions are determined. The small parameter method separates the non-linear system of partial differential equations and creates several linear systems of equations. The aim of this work is to derive the equations describing and allowing the determination of the temperature distribution, hydrodynamic pressure distribution, velocity vector components, load carrying capacity, friction force and friction coefficient in the gap of conical slide bearing, lubricated with the oil of the properties described by the Rivlin-Ericksen model, taking into account its viscosity changes due to time of operation.
W artykule autorzy przedstawiają równania hydrodynamicznej teorii smarowania olejem o modelu Rivlina-Ericksena stożkowego łożyska ślizgowego. Olej ten charakteryzuje się nienewtonowskimi właściwościami, czyli jest to olej, dla którego, oprócz klasycznych zależności lepkości oleju od ciśnienia, temperatury i czasu eksploatacji, występuje dodatkowo zmiana lepkości dynamicznej od szybkości ścinania. Do rozwiązania równań zachowania pędu, ciągłości strugi i zachowania energii wykorzystano metodę małego parametru. Metoda ta polega na przedstawieniu poszukiwanych funkcji (ciśnienia, temperatury, składowych wektora prędkości) w formie jednostajnie zbieżnego szeregu potęgowego rozwiniętego względem stałego małego parametru. Funkcje te podstawia się do układu równań podstawowych, a następnie wymnaża te szeregi metodą Cauchy’ego. Porównując współczynniki przy jednakowych potęgach małego parametru, otrzymuje się układy równań różniczkowych cząstkowych, z których wyznacza się kolejne przybliżenia niewiadomych, poszukiwanych funkcji. Metoda małego parametru rozprzęga nieliniowy układ równań różniczkowych cząstkowych, tworząc kilka liniowych układów równań. Celem niniejszej pracy jest wyprowadzenie równań umożliwiających wyznaczenie rozkładu temperatury, rozkładu ciśnienia hydrodynamicznego, składowych wektora prędkości, siły nośnej, siły tarcia i współczynnika tarcia w szczelinie poprzecznego łożyska ślizgowego smarowanego olejem o modelu Rivlina-Ericksena z uwzględnieniem zmian lepkości od czasu eksploatacji oleju.
Źródło:
Tribologia; 2019, 284, 2; 83-95
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of phenomena accompanying ring collaboration with worn cylinder surface
Analiza zjawisk towarzyszących współpracy pierścienia tłokowego ze zużytą powierzchnią gładzi cylindra
Autorzy:
Serdecki, W.
Krzymień, P.
Powiązania:
https://bibliotekanauki.pl/articles/132948.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
piston ring
oil film
ring wall pressure
pierścień tłokowy
film olejowy
rozkład nacisków pierścienia
Opis:
The presented study which refers to the earlier papers of the authors discusses an effect of cylinder wall deformation on the effectiveness of compression ring operation. Presented models permit a mathematical description of a deformed cylinder and definition of ring wall pressure relative to these deformations. The drafts presented in the paper, obtained in a course of calculations of a compression ring installed in a work machine engine, allow to evaluate the effect of cylinder deformations on distribution of ring circumferential pressure and point out areas where the light slots could occur.
W niniejszej pracy, wiążącej się tematycznie z wcześniejszymi publikacjami autorów, określono wpływ zmian kształtu otworu cylindra na skuteczność pracy pierścienia uszczelniającego. Zaprezentowano modele, umożliwiające matematyczny opis odkształconego otworu cylindra, a także wyznaczenie odpowiadającego tym odkształceniom nacisku pierścienia na gładź cylindra. Na zamieszczonych w opracowaniu wykresach, uzyskanych podczas obliczeń pierścienia uszczelniającego pracującego w silniku spalinowym maszyny roboczej, pokazano przebiegi pozwalające ocenić wpływu wartości zniekształcenia otworu cylindra na rozkład nacisków obwodowych, a także wskazano miejsca, w których możliwe jest pojawienie się tzw. szczelin świetlnych.
Źródło:
Combustion Engines; 2013, 52, 2; 40-47
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biodegradowalne oleje smarowe do przelotowych układów smarowania
Biodegradable lubricants for total loss systems
Autorzy:
Rogoś, E.
Powiązania:
https://bibliotekanauki.pl/articles/190883.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
oleje roślinne
olej gorczycowy
właściwości przeciwzużyciowe
właściwości przeciwzatarciowe
właściwości fizykochemiczne
vegetable oils
mustard oil
antiwear properties
extreme-pressure properties physicochemical properties
Opis:
Przedstawiono wyniki badań kompozycji olejowych o klasie lepkości ISO VG 32, 46 i 68, przeznaczonych do stosowania w przelotowych układach smarowania. Bazą kompozycji była mieszanina oleju gorczycowego z olejem rycynowym lub estrami metylowymi oleju rzepakowego. Oceniono właściwości przeciwzużyciowe, przeciwzatarciowe, fizykochemiczne i ekologiczne produktów. Dla porównania zbadano takie same właściwości olejów maszynowych rodzaju AN przeznaczonych do smarowania przelotowego maszyn i urządzeń. Stwierdzono, że wytworzone kompozycje olejowe charakteryzowały się takimi samymi lub wyższymi od produktów komercyjnych właściwościami przeciwzużyciowymi i przeciwzatarciowymi, lepkościowo-temperaturowymi, przeciwkorozyjnymi, przeciwpiennymi i termooksydacyjnymi. Mogły być stosowane w przelotowych układach smarowania pracujących w zmiennych warunkach klimatycznych, np. mechanizmów smarowania mgłą olejową w leśnictwie i sadownictwie czy osi pojazdów szynowych.
The objects of this study were oils for total loss systems with ISO VG 32, 46, and 68 viscosity grade. The oils were manufactured based on mixture of mustard oil with castor oil or rapeseed-methyl-ester. Antiwear, extreme-pressure, and physicochemical properties of these oils were assessed. They were compared to “classical” mineral-based machinery oils of category AN. The results indicated that the vegetable-based oils were comparable to the mineral oils and they can be used as their substitute.
Źródło:
Tribologia; 2015, 1; 109-120
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Capacity forces in slide journal plane bearing by laminar unsteady lubrication
Autorzy:
Krasowski, P.
Powiązania:
https://bibliotekanauki.pl/articles/247548.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
journal plane bearing
lubrication
unsteady laminar oil flow
pressure distribution
capacity forces
Opis:
This paper shows results of numerical solutions an modified Reynolds equations for laminar unsteady oil flow in slide journal bearing with planar linear gap. Discussed case of the solution to the Reynolds equation for the unsteady laminar Newtonian flow of lubricating factor allows initial estimation of hydrodynamic pressure distribution and its capacity as a basic operational parameter of the slide bearing. Unsteady axial velocity perturbation on the race surface and slide has influence on the hydrodynamic pressure distribution of the capacity of the lubricated gap. Pressure changes in the bearing are seasonal and equal to the lasting period of velocity perturbation. The level of changes and its nature depends on the kind of perturbation. This solution example applies to isothermal bearing model with infinity length. Lubricating oil used in this model has Newtonian properties and dynamic viscosity in dependence on pressure. It shows a preliminary analysis change of capacity forces in the bearing by laminar, unsteady lubrication caused by velocity perturbations of oil flow in the longitudinal direction of a bearing. Described effect can be used as an example of modeling the bearing friction node operations in reciprocating movement during exploitation of engines and machines. Plane crossbar journal bearing occur in ship combustion engine as a crosshead bearing. Results are presented in the dimensionless hydrodynamic pressure and capacity force diagrams.
Źródło:
Journal of KONES; 2008, 15, 3; 245-252
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Carrying capacity and friction forces in a transverse journal bearing, lubricated with non-Newtonian oil
Autorzy:
Miszczak, A.
Sikora, G.
Powiązania:
https://bibliotekanauki.pl/articles/243066.pdf
Data publikacji:
2017
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
slide journal bearing
hydrodynamic pressure
load carrying capacity
friction force
non-Newtonian oil
Opis:
In this article, the authors present the results of numerical calculations. Calculations concern dimensionless carrying capacity and friction forces in a transverse journal bearing, lubricated by the oil of non-Newtonian properties. For analytical-numerical considerations a model of apparent viscosity changes based on exploitation time, pressure, temperature, shear rate was assumed The non-Newtonian properties of lubricating oil were characterized by increasing viscosity with increasing shear rate and described as an additional part in the constitutive equationβ3·tr(A1 2)A1. Analytical-numerical calculations were performed for smooth, non-porous plain bearing with full angle of wrap. Non-isothermal, laminar and fixed flow of lubricant in the lubrication gap of the journal bearing was assumed. Numerical calculations of hydrodynamic pressure distribution were made for Reynolds boundary conditions. The finite difference method was used to determine the Reynolds equation and the successive approximation method by taking into account the influence of pressure, temperature and non-Newtonian properties on the change of apparent viscosity. The results of the calculations are presented in the form of graphs and tables illustrating the influence of relative eccentricity and pressure, temperature and non-Newtonian properties on changes in the dimensionless load and friction force. Analysis of the obtained results illustrates the high-pressure effect on the increase of the carrying capacity and friction force for high relative eccentricities. A similar situation is by considering the non-Newtonian properties.
Źródło:
Journal of KONES; 2017, 24, 3; 203-210
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of hydrodynamic lubrication of slide conical bearing with consideration of the bearing shaft and sleeve surface roughness
Autorzy:
Czaban, A
Powiązania:
https://bibliotekanauki.pl/articles/246600.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical bearing
surface roughness
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
pressure distribution
sand-grain roughness
Opis:
In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of the effect of the bearing shaft and sleeve surface roughness. The oil flow in a bearing lubrication gap largely depend on the condition of the cooperating surfaces of a bearing. Surface irregularities are formed already at the manufacturing process and furthermore the quality of the surface may change during operation of a bearing. In this work, as a parameter describing surface condition, the Ks roughness height parameter was taken (i.e. sand-grain roughness height). The hydrodynamic pressure distribution in lubrication gaps of investigated bearings were calculated by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were conducted for bearings without misalignment. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that bearings have smooth surfaces and there is no slip on surfaces. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:
Journal of KONES; 2014, 21, 3; 35-40
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of non-Newtonian and non-isothermal lubrication of hydrodynamic conical bearing
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/243876.pdf
Data publikacji:
2014
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
conical bearing
hydrodynamic lubrication
CFD simulation
non-Newtonian oil
non-isothermal flow
pressure distribution
Opis:
In this work is shown the result of CFD simulation of hydrodynamic conical bearing lubrication with consideration of non-isothermal oil flow in a bearing lubrication gap and also with assumption, that oil has non- Newtonian properties. The determination of hydrodynamic pressure distribution in bearing gap was carried out by using the commercial CFD software ANSYS Academic Research for fluid flow phenomenon (Fluent). Calculations were performed for bearings without misalignment, i.e. where the cone generating line of bearing shaft is parallel to the cone generating line of bearing sleeve. The Ostwald-de Waele model for non-Newtonian fluids was adopted in this simulation. The coefficients of Ostwald-de Waele relationship were determined by application of the least squares approximation method and fitting curves described by this model to the experimental data, obtained for some motor oils, presented in previous work. The calculated hydrodynamic pressure distributions were compared with the data obtained for corresponding bearings, but assuming that the flow in the bearing lubrication gap is isothermal. Some other simplifying assumptions are: a steady-state operating conditions of a bearing, incompressible flow of lubricating oil, no slip on bearing surfaces, pressure on the side surfaces of bearing gap is equal to atmospheric pressure. This paper presents results for bearings with different rotational speeds and of different bearing gap heights.
Źródło:
Journal of KONES; 2014, 21, 4; 49-56
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
CFD analysis of pressure distribution in slide conical bearing lubricated with non-Newtonian oil
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/241851.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
slide conical bearing
CFD
non-Newtonian oil
pressure distribution
Źródło:
Journal of KONES; 2013, 20, 3; 117-124
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crude oil transfer safety analysis and oil spills prevention in port oil terminal
Autorzy:
Blokus, Agnieszka
Kwiatuszewska-Sarnecka, Bożena
Wilczyński, Przemysław
Wolny, Paweł
Powiązania:
https://bibliotekanauki.pl/articles/2068697.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Morski w Gdyni. Polskie Towarzystwo Bezpieczeństwa i Niezawodności
Tematy:
oil port terminal
oil transfer
operation process
system reliability
oil spill
human factor
pressure upsurge
safety procedures
ESD System
LCH Simulator
Opis:
The paper describes the problem of crude oil transfer in a port oil terminal and includes the safety analysis of this operation and analysis of potential causes and possible scenarios of oil spill events in a port terminal. The operation process of crude oil transfer is described and its statistical identification is given. The reliability and availability analysis of the system of crude oil transfer in a port terminal is performed. Moreover, analysis of crude oil transfer process taking into account the human factor is provided. The Fault Tree Analysis and sensitivity analysis for oil spill event in a port terminal is proposed to identify and analyse potential causes and possible scenarios of oil spill. Introducing methods for the prevention of oil spills, special attention is paid to safety procedures during liquid cargo transfer. Technical solutions used in oil terminals are described and recommendation regarding the Emergency Shutdown System are given. Additionally, associated safety systems, such as surge relief system, are described. Emphasizing the role of human factor in the process of crude oil transfer and its safety, trainings on the Liquid Cargo Handling Simulator are proposed to improve skills and knowledge of personnel on board and ashore.
Źródło:
Journal of Polish Safety and Reliability Association; 2019, 10, 1; 1--42
2084-5316
Pojawia się w:
Journal of Polish Safety and Reliability Association
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation the Effect of Adding Oil Shale Ash on the Compressive Strength of Concrete
Autorzy:
Gougazeh, Mousa
Powiązania:
https://bibliotekanauki.pl/articles/2201819.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
oil shale ash
compressive strength
compaction pressure
combustion
construction
sustainable
Opis:
In the present study, the effect of cementing properties of oil shale ash on the compressive strength of the concrete mixtures produced from oil shale ash, cement, sand, and water was investigated. The used shale ash was produced by direct combustion at 830oC in a laboratory muffle furnace of the El-Lajjun oil shale. Based on the chemical composition of shale ash (OSA), it was concluded that this material consists of a high percentage of CaO which forms the properties of cement materials as well as the contents of SiO2, Al2O3, and Fe2O3 form the properties of pozzolanic materials. Oil shale ash (OSA) materials have diverse applications as alternative materials for the construction industry and construction technology to reduce environmental risks and achieve sustainability. The results showed that the pressed specimen with 40 wt. % OSA content, 50 wt. % sand content and 30% MW obtained the highest compressive strength of about 9.1 MPa after 28 days of hardening. The highest value of 28 days compressive strength for a compacted specimen containing 35 wt. % OSA and 35% MW were achieved with 12 MPa at a compaction pressure of between 25 and 30 MPa. High compressive strength values were found to be achieved in the compressed specimens by controlling mixing water. It is also indicated that the compressive strength increases as OSA content in the compressed specimen increases and increases as compaction pressure increases.
Źródło:
Advances in Science and Technology. Research Journal; 2022, 16, 4; 130--137
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized Newtonian fluids as lubricants in the hydrodynamic conical bearings : a CFD analysis
Autorzy:
Czaban, A.
Powiązania:
https://bibliotekanauki.pl/articles/242462.pdf
Data publikacji:
2016
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
hydrodynamic conical bearing
generalized Newtonian fluid
CFD
non-Newtonian oil
pressure distribution
dynamic viscosity
ferro-oil
Opis:
Additives, ageing or wear and impurities can cause, that relationship between shear stress and shear rate in a lubricating oil is or becomes non-linear, and due to this, a significant change in the values of operating parameters of slide hydrodynamic bearings may occur. It is important to take into account such dependence during design and simulations of slide bearings. The calculations, which consider the non-linear properties of the lubricating oil, can be carried out by adopting the generalized Newtonian fluid models. This paper shows the result of CFD simulation of slide conical bearings hydrodynamic lubrication, assuming that the lubricating oil behaves as a generalized Newtonian fluid. The hydrodynamic pressure distributions, load carrying capacities and friction torques were calculated for bearings lubricated with different types of generalized Newtonian fluids and the obtained data were compared. In the study, the following models of fluids were adopted: the Power-law fluid (Ostwald-de Waele), the Cross fluid and the Carreau fluid. The coefficients of mentioned relationships were determined by fitting the curves described by each model to the experimental data using the least squares approximation method. The calculations of hydrodynamic pressure distributions, load carrying capacities and friction torques were carried out using the commercial CFD software Ansys Fluent from the Ansys Workbench 2 platform.
Źródło:
Journal of KONES; 2016, 23, 2; 89-95
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of pressure on dynamic viscosity of oil
Autorzy:
Czaban, A.
Frycz, M.
Powiązania:
https://bibliotekanauki.pl/articles/242263.pdf
Data publikacji:
2013
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
dynamic viscosity
engine oil
pressure dependence
temperature dependence
shear rate
Opis:
The viscosity of lubricant is physical quantity, which has major impact on slide bearings and micro-bearings functioning parameters. Applying computer simulations as a tool to study the hydrodynamic lubrication phenomenon, researcher should create a computational model as close as possible to the real object, therefore the knowledge about a viscosity dependence on temperature and shear rate of bearing lubricating oil is essential in simulations of slide bearings hydrodynamic lubrication. This paper present research, which show, that also an influence of pressure on oil dynamic viscosity should be taken into consideration. The aim of this work is to determine the influence of pressure on the dynamic viscosity of lubricating oil. In this research the selected new and used engine oils were investigated. The dynamic viscosity of oil was measured at different pressures and temperatures in the function of shear rate. In this work the engine oils of passenger vehicles were investigated. The viscosity measurements for new and used lubricating oils were made with the Thermo Scientific Haake Mars III rheometer. The received information will be used in the simulations of hydrodynamic lubrication of slide bearings and microbearings. Fitting viscosity curves, described by a viscosity model adopted in simulations, to the experimental data, obtained for motor oils, will allow to find the values of coefficients of that model. The determined coefficients will be set in the relationship defined by the adopted viscosity model, implemented in the used for simulations CFD software. Collected data may also be useful for designing bearings and sliding friction pairs.
Źródło:
Journal of KONES; 2013, 20, 2; 49-54
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integration and verification of miniature fluid film pressure sensors in hydrodynamic linear guides
Autorzy:
Ibrar, Burhan
Wittstock, Volker
Regel, Joachim
Dix, Martin
Powiązania:
https://bibliotekanauki.pl/articles/24084705.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
hydrodynamic linear guide
measurement technology
oil film
pressure measurement
Opis:
Previously, a 2D simulation model for hydrodynamic linear guides with two reduction factors has been developed to calculate oil film pressure and floating heights/angle numerically. However, no method was available to verify the oil film pressure experimentally but only with floating heights measurement. Therefore, different pressure sensor’s integration methods were tested in a stationary Plexiglas rail to measure fluid film pressure inside the lubrication gap. The pressure sensors were statically and dynamically calibrated. However, floating heights could not be measured with the preliminary used Plexiglas rail. This paper reports the suitable integration of pressure sensors into a stationary steel rail to compensate this drawback. It focuses on the measurement of pressure rise using pressure sensors inside the lubrication gap in combination with the floating heights. Experimental results have shown that the oil film pressure inside the lubrication gap can be measured using pressure sensors, which draw conclusions about cavitation and lack of lubrication. The variation of oil film pressure measured along the length of the carriage can be used to improve the simulation model i.e. the reduction factors. The pressure measurement can help to identify the lubrication conditions and further actions can be taken to improve the lubrication cycle.
Źródło:
Journal of Machine Engineering; 2023, 23, 3; 38--55
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 42

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