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Wyszukujesz frazę "heat mass transfer" wg kryterium: Temat


Tytuł:
Increasing of efficiency of the cooling duct by modification of its geometry
Autorzy:
Kiedrzyński, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/240839.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
duct electrochemical limiting current technique
ELDCT
heat mass transfer
efficiency
Opis:
Increasing of the efficiency of convective cooling of the inner surface of a short duct by changing its geometry was studied by the use of electrochemical limiting current technique (ELDCT). The duct consisted of seven identical, cylindrical segments. The changes of the duct geometry were obtained by mutual displacement of neighbouring segments, towards the radial direction. Mean values of the mass transfer coefficient for each segment and friction losses for the whole channel were measured for Reynolds numbers spanning the range 7700–35300 at the five values of displacement parameter. The results were used for estimation of cooling efficiency. Recommended values of displacement were determined to point the favourable conditions of heat/mass transfer in the duct. The results may be used, e.g. in the design of heat exchangers and channels for cooling of turbine blades and electronic equipment.
Źródło:
Archives of Thermodynamics; 2020, 41, 3; 103-123
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat and mass transfer mechanism on three-dimensional flow of inclined magneto Carreau nanofluid with chemical reaction
Autorzy:
Rao, B. Madhusudhana
Gopal, Degavath
Kishan, Naikoti
Ahmed, Saad
Prasad, Putta Durga
Powiązania:
https://bibliotekanauki.pl/articles/240005.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
carreau nanofluid
chemical reaction
MHD
heat and mass transfer
Opis:
The characteristic of nano sized particles mass flux conditions are engaged in this investigation. Here we assume that the nano sized particle flux is zero and the nano sized particle fraction arranged itself on the boundary layer. With this convincing and revised relation, the features of Buongiorno relation on three-dimensional flow of Carreau fluid can be applied in a more efficient way. The governing partial differential equations of continuity, momentum, energy and concentration equations which are transmitted into set of pair of nonlinear ordinary differential equations utilizing similar transformations. The numeric solutions are acquired by engaging the bvp4c scheme, which is a finite-difference code for solving boundary value problems. A parametric study is accomplished to demonstrate the impact of Prandtl number, Weissenberg numbers, radiation parameter, chemical reaction parameter, thermophoresis parameter, Brownian motion parameter and Lewis number on the fluid velocity, temperature and concentration profiles as well skin friction coefficient, Nusselt number and Sherwood number within the boundary layer. From this we find the way in which magnetic parameter contributes to the increase in local skin fraction, and the decrease in the Nusselt and Sherwood numbers in these cases. The effects of the velocity temperature and concentration profile are obtained and presented graphically.
Źródło:
Archives of Thermodynamics; 2020, 41, 2; 223-238
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of Steam Formation and Migration in Firefighters’ Protective Clothing Using X-Ray Radiography
Autorzy:
Keiser, C.
Wyss, P.
Rossi, R. M.
Powiązania:
https://bibliotekanauki.pl/articles/89736.pdf
Data publikacji:
2010
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
X-ray radiography
evaporation
steam transfer
protective clothing
firefighting
heat and mass transfer
Opis:
X-ray radiography was used to quantify evaporation and moisture transfer in a multilayer firefighter protective clothing system with defined wetted layers exposed to low thermal radiation. Evaporation was faster and took place at higher temperatures if the moisture was located in the outer layers of the clothing system. Moisture that evaporated in the outer layers of the clothing system was found to move inwards and condense in the inner layers and on the cap of the measurement cell. Results found in this study correlated well with the findings of our former study based on simple temperature distribution measurements to determine moisture transfer in protective clothing layers at low level thermal radiation.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2010, 16, 2; 217-229
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bidirectionally stretched flow of Jeffrey liquid with nanoparticles, Rosseland radiation and variable thermal conductivity
Autorzy:
Archana, M.
Gireesha, B. J.
Rashidi, M. M.
Prasannakumara, B. C.
Gorla, R. S. R.
Powiązania:
https://bibliotekanauki.pl/articles/240409.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heat mass transfer
jeffrey nanofluid
variable thermal conductivity
rosseland approximation
suction
ciepło
masa
zmienna przewodność cieplna
aproksymacja
ssanie
Opis:
Heat and mass transfer stretched flow of an incompressible, electrically conducting Jeffrey fluid has been studied numerically. Nanoparticles are suspended in the base fluid and it has many applications such as cooling of engines, thermal absorption systems, lubricants fuel cell, nanodrug delivery system and so on. Temperature dependent variable thermal conductivity with Rosseland approximation is taken into account and suction effect is employed in the boundary conditions. The governing partial differential equations are first transformed into set of ordinary differential equations using selected similarity transformations, which are then solved numerically using Runge-Kutta-Felhberg fourth-fifth order method along with shooting technique. The flow, heat and mass transfer characteristics with local Nusselt number for various physical parameters are presented graphically and a detailed discussion regarding the effect of flow parameters on velocity and temperature profiles are provided. It is found that, increase of variable thermal conductivity, radiation, Brownian motion and thermophoresis parameter increases the rate of heat transfer. Local Nusselt number has been computed for various parameters and it is observed that, in the presence of variable thermal conductivity and Rosseland approximation, heat transfer characteristics are higher as compared to the constant thermal conductivity and linear thermal radiation.
Źródło:
Archives of Thermodynamics; 2018, 39, 4; 33--57
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zmiana efektywności wymiany masy i ciepła poprzez zastosowanie warstw antykondensacyjnych
Changing the efficiency of heat and mass transfer through the use of anti-condensation layer
Autorzy:
Grzebielec, A.
Rusowicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/271263.pdf
Data publikacji:
2014
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Aparatury Badawczej i Dydaktycznej, COBRABiD
Tematy:
wymiana ciepła i masy
warstwy antykondensacyjne
heat and mass transfer
anti-condensation layer
Opis:
W wielu dziedzinach techniki, zwłaszcza związanych z przechowywaniem i transportem żywności, można spotkać się z przegrodami budowlanymi, które w pewnych okresach są zawilgocone. Powstawanie wilgoci związane jest głównie z procesem chłodzenia, ale jest także naturalnym zjawiskiem w godzinach porannych – na zewnętrznych stronach przegród budowlanych. Pojawianie się kropel wody na nieosłoniętych powierzchniach powoduje, że intensyfikuje się proces wymiany ciepła przez te przegrody, a one same także ulegają degradacji. Przedstawiona praca ma na celu pokazać, w jaki sposób zmienia się to zjawisko, gdy stosowane są warstwy antykondensacyjne. Praca przedstawia badania eksperymentalne, jak i wyniki modelowania matematycznego opisywanego zjawiska.
In many areas of technology, especially relating to the storage and transport of food you can meet with baffles building, which at certain times are damp. Formation of moisture is mainly related to the cooling process. But it is also a natural phenomenon in the morning – on the outer sides of the building envelope. The appearance of water droplets results in a process that enhances heat transfer through the barrier, and they are degraded. This paper aims to show how to change this phenomenon when applied anti-condensation layer. The paper presents experimental studies and the results of mathematical modeling of this phenomenon.
Źródło:
Aparatura Badawcza i Dydaktyczna; 2014, 19, 1; 93-97
2392-1765
Pojawia się w:
Aparatura Badawcza i Dydaktyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of a chemically reactive MHD flow with heat and mass transfer over a permeable surface
Autorzy:
Fenuga, O. J.
Aroloye, S. J.
Popoola, A. O.
Powiązania:
https://bibliotekanauki.pl/articles/266282.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
transfer ciepła
transfer masy
przepływ magnetohydrodynamiczny
powierzchnia przepuszczalna
heat and mass transfer
chemically reactive MHD flow
permeable surface
Opis:
This paper investigates a chemically reactive Magnetohydrodynamics fluid flow with heat and mass transfer over a permeable surface taking into consideration the buoyancy force, injection/suction, heat source/sink and thermal radiation. The governing momentum, energy and concentration balance equations are transformed into a set of ordinary differential equations by method of similarity transformation and solved numerically by Runge- Kutta method based on Shooting technique. The influence of various pertinent parameters on the velocity, temperature, concentration fields are discussed graphically. Comparison of this work with previously published works on special cases of the problem was carried out and the results are in excellent agreement. Results also show that the thermo physical parameters in the momentum boundary layer equations increase the skin friction coefficient but decrease the momentum boundary layer. Fluid suction/injection and Prandtl number increase the rate of heat transfer. The order of chemical reaction is quite significant and there is a faster rate of mass transfer when the reaction rate and Schmidt number are increased.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 1; 53-66
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of temperature of rocks on microclimatic conditions in long gate roads and galleries in coal mines
Wpływ temperatury pierwotnej skał na parametry mikroklimatu w długich wyrobiskach korytarzowych
Autorzy:
Cygankiewicz, J.
Knechtel, J.
Powiązania:
https://bibliotekanauki.pl/articles/219812.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
bezpieczeństwo
aerologia
klimatyzacja
przepływ ciepła i masy
safety
ventilation
air-conditioning
heat and mass transfer
Opis:
The aim of this study was to examine the effect of the temperature of surrounding rocks on enthalpy and temperature of air flowing along several model mine workings. Long workings surrounded by non- -coal rocks as well longwall gates surrounded by coal were taken into consideration. Computer-aided simulation methods were used during the study. At greater depths the amount of moisture transferred into a mine working from the rock mass is two orders of magnitude smaller than the moisture that comes from external (technological) sources, mainly from coal extraction-related processes, therefore in the equation describing temperature changes only the terms representing the flux of heat from rocks were included. The model workings, for calculation purposes, were divided into sections, 50 m in length each. For each of the sections temperature of its ribs and temperature and stream of enthalpy of air flowing along it were calculated with the use of the finite differences method. For workings surrounded by non-coal rocks two variant calculations were carried out, namely with or without technological sources of heat. For coal surrounded workings (longwall gates) a new method for determination of heat from coal oxidation was developed, based on the findings by Cygankiewicz J. (2012a, 2012b). Using the results of a study by J.J. Drzewiecki and Smolka (1994), the effects of rock mass fracturing on transfer of heat into the air stream flowing along a working were taken into account.
Badano wpływ temperatury pierwotnej skał na strumień entalpii oraz temperaturę powietrza w wyrobisku korytarzowym o długości 2000 m. Rozpatrywano wyrobiska kamienne oraz chodniki podścianowe. W badaniach zastosowano metodę symulacji komputerowych. Na dużych głębokościach wilgoć przenoszona z górotworu do wyrobiska jest dwa rzędy wielkości mniejsza od wilgoci pochodzącej od procesów technologicznych. W związku z powyższym w równaniu opisującym zmiany temperatury w masywie skalnym uwzględniono tylko człon reprezentujący ruch ciepła w skałach. Badane wyrobisko podzielono na odcinki o długości 50 m. Korzystając z metody różnic skończonych dla każdego z odcinków wyznaczono temperaturę ociosu, a następnie temperaturę i strumień entalpii powietrza. W odniesieniu do wyrobisk kamiennych rozważania przeprowadzono dla wariantu z technologicznymi źródłami ciepła oraz bez takich źródeł. Dla chodników węglowych przedstawiono nowy sposób określenia ciepła utleniania węgla, na podstawie wyników badań J. Cygankiewicza (2012a, 2012b). Korzystając z wyników badań J. Drzewieckiego i J. Smołki (1994), uwzględniono wpływ spękań górotworu na przenoszenie ciepła do powietrza w wyrobisku.
Źródło:
Archives of Mining Sciences; 2014, 59, 1; 189-216
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie termowizji do badań biotribologii stawu łokciowego
The use of thermography to the study of the elbow biotribology
Autorzy:
Piwnik, J.
Rusowicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/190718.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
biotribologia stawu łokciowego
termowizja
wymiana ciepła i masy
biotribology elbow
thermography
heat and mass transfer
Opis:
W pracy przedstawiono analizę strumieni ciepła pochodzących od tarcia z obciążonego stawu łokciowego. W badaniach wykorzystano zdjęcia termowizyjne do określenia temperatur powierzchni skóry i strumieni ciepła jawnego i utajonego.
The paper presents an analysis of the heat flux coming from the friction of the loaded elbow. The study used infrared images to determine the skin surface temperature and heat flux of sensible and latent heat.
Źródło:
Tribologia; 2013, 1; 117-124
0208-7774
Pojawia się w:
Tribologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
First order chemical reaction effects on exponentially accelerated vertical plate with variable mass diffusion in the presence of thermal radiation
Autorzy:
Muthucumaraswamy, R.
Lakshmi, C. S.
Powiązania:
https://bibliotekanauki.pl/articles/264881.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
exponential
radiation
isothermal
vertical plate
heat and mass transfer
promieniowanie
izoterma
wymiana ciepła
wymiana masy
Opis:
Effects of transfer of mass and free convection on the flow field of an incompressible viscous fluid past an exponentially accelerated vertical plate with variable surface temperature and mass diffusion are studied. Results for velocity, concentration, temperature are obtained by solving governing equations using the Laplace transform technique. It is observed that the velocity increases with decreasing values of the chemical reaction parameter or radiation parameter. But the trend is just reversed with respect to the time parameter. The skin friction is also studied.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 2; 329-344
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two-dimensional CFD modeling of the heat and mass transfer process during sewage sludge drying in a solar dryer
Autorzy:
Krawczyk, P.
Badyda, K.
Powiązania:
https://bibliotekanauki.pl/articles/240601.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
suszenie osadów ściekowych
wymiana ciepła i masy
CFD
heat and mass transfer
sewage sludge drying
Opis:
The paper presents key assumptions of the mathematical model which describes heat and mass transfer phenomena in a solar sewage drying process, as well as techniques used for solving this model with the Fluent computational fluid dynamics (CFD) software. Special attention was paid to implementation of boundary conditions on the sludge surface, which is a physical boundary between the gaseous phase - air, and solid phase - dried matter. Those conditions allow to model heat and mass transfer between the media during first and second drying stages. Selection of the computational geometry is also discussed - it is a fragment of the entire drying facility. Selected modelling results are presented in the final part of the paper.
Źródło:
Archives of Thermodynamics; 2011, 32, 4; 3-16
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wyznaczanie współczynników wnikania masy podczas odparowania cienkowarstewkowego roztworu przy wykorzystaniu wyników destylacji lub wyników badań ruchu ciepła
Determination of mass transfer coefficients during the thin-layer solution evaporation using distillation or heat transfer results
Autorzy:
Dziak, J.
Kubala, M.
Kapłon, J.
Ludwig, W.
Powiązania:
https://bibliotekanauki.pl/articles/2070877.pdf
Data publikacji:
2010
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
wyparka cienkowarstewkowa
roztwór
ruch ciepła
ruch masy
thin-layer evaporator
liquid solutions
heat and mass transfer
Opis:
W pracy przedstawiono wyniki badań eksperymentalnych ruchu ciepła i masy podczas odparowania cieczy w wyparce cienkowarstewkowej. Wyznaczono współczynniki wnikania ciepła podczas wrzenia cieczy jednoskładnikowych i roztworów. Wyniki destylacji w układzie alkohol izopro-pylowy - woda porównano z wynikami obliczeń teoretycznych. Stwierdzono wyraźne różnice. Wyznaczono wartości współczynników wnikania masy podczas wrzenia roztworu. Zastosowano dwie różne metody postępowania. Uzyskano podobne wyniki.
Results of experimental investigations on heat and mass transfer during liquid evaporation in a thin-layer evaporator are presented. Individual heat transfer coefficients were determined. The results of distillation of isopropyl alcohol - water solutions were obtained. Significant deviations of theoretical results in comparison with experimental ones were confirmed. Individual mass transfer coefficients were determined applying two different methods. Both methods gave similar results.
Źródło:
Inżynieria i Aparatura Chemiczna; 2010, 2; 37-38
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling of heat and mass transfer during thermal decomposition of a single solid fuel particle
Autorzy:
Wardach-Święcicka, I.
Kardaś, D.
Powiązania:
https://bibliotekanauki.pl/articles/240457.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fuel particles
devolatilization
pyrolysis
heat and mass transfer
ziarna paliwa
odgazowanie
piroliza
wymiana ciepła i masy
Opis:
The aim of this work was to investigate the heat and mass transfer during thermal decomposition of a single solid fuel particle. The problem regards the pyrolysis process which occurs in the absence of oxygen in the first stage of fuel oxidation. Moreover, the mass transfer during heating of the solid fuels is the basic phenomenon in the pyrolysis-derived alternative fuels (gas, liquid and solid phase) and in the gasification process which is focused on the generation of syngas (gas phase) and char (solid phase). Numerical simulations concern pyrolysis process of a single solid particle which occurs as a consequence of the particle temperature increase. The research was aimed at an analysis of the influence of particle physical properties on the devolatilization process. In the mathematical modeling the fuel grain is treated as an ideal sphere which consists of porous material (solid and gaseous phase), so as to simplify the final form of the partial differential equations. Assumption that the physical properties change only in the radial direction, reduces the partial derivatives of the angular coordinates. This leads to obtaining the equations which are only the functions of the radial coordinate. The model consists of the mass, momentum and energy equations for porous spherical solid particle heated by the stream of hot gas. The mass source term was determined in the wide range of the temperature according to the experimental data. The devolatilization rate was defined by the Arrhenius formula. The results of numerical simulation show that the heating and devolatilization time strongly depend on the physical properties of fuel. Moreover, proposed model allows to determine the pyrolysis process direction, which is limited by the equilibrium state.
Źródło:
Archives of Thermodynamics; 2013, 34, 2; 53-71
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mass transfer with chemical reaction on flow past an accelerated vertical plate with variable temperature and thermal radiation
Autorzy:
Muthucumaraswamy, R.
Balachandran, P.
Ganesan, K.
Powiązania:
https://bibliotekanauki.pl/articles/264786.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
reakcja chemiczna
promieniowanie
wymiana ciepła i masy
linearly accelerated
chemical reaction
radiation
heat and mass transfer
Opis:
An exact solution of an unsteady radiative flow past a uniformly accelerated infinite vertical plate with variable temperature and mass diffusion is presented here, taking into account the homogeneous chemical reaction of first order. The plate temperature as well as concentration near the plate is raised linearly with time. The dimensionless governing equations are solved using the Laplace-transform technique. The velocity, temperature and concentration fields are studied for different physical parameters such as the thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number, radiation parameter, chemical reaction parameter and time. It is observed that the velocity increases with increasing values of the thermal Grashof number or mass Grashof number. But the trend is just reversed with respect to the thermal radiation parameter. It is also observed that the velocity increases with the decreasing chemical reaction parameter.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 945-953
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical solution for magnetohydrodynamic stagnation point flow and heat transfer over a permeable stretching sheet with chemical reaction
Autorzy:
Rasekh, A.
Farzaneh-Gord, M.
Varedi, S. R.
Ganji, D. D.
Powiązania:
https://bibliotekanauki.pl/articles/279659.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
MHD stagnation point flow
permeable stretching sheet
heat and mass transfer
Optimal Homotopy Asymptotic Method (OHAM)
Opis:
This work deals with the problem of steady two-dimensional magnetohydrodynamic (MHD) stagnation point flow towards a permeable stretching sheet with chemical reaction. The fundamental equations of the boundary layer are transformed into ordinary differential equations, which are then solved analytically using the Optimal Homotopy Asymptotic Method (OHAM). Comparisons are made between the results of the proposed method and the numerical method (fourth-order Runge-Kutta) in solving this problem, and excellent agrement has been observed. Subsequently, effects of different involved parameters on the temperature profiles, concentration profiles, local Nusselt number, local Sherwood number and skin-friction coefficient are presented and discussed in detail.
Źródło:
Journal of Theoretical and Applied Mechanics; 2013, 51, 3; 675-686
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On problems of heat and mass transfer in concrete structures
Metoda stochastycznych różnic skończonych w problemach przepływu ciepła i ruchu wilgoci w elemencie betonowym
Autorzy:
Kowalik, M.
Poński, M.
Powiązania:
https://bibliotekanauki.pl/articles/2067862.pdf
Data publikacji:
2016
Wydawca:
Politechnika Częstochowska
Tematy:
concrete
heat and mass transfer
uncertainty
perturbation method
beton
przepływ ciepła i masy
losowość
metoda perturbacyjna
Opis:
A stochastic finite difference approach based on stochastic finite elements is proposed for heat and mass transfer modeling. Porous structure with random material properties is investigated. The theoretical formulation of the problem is described. A system of partial differential equations is obtained and solved for first two probabilistic moments of the random temperature field. Example of stochastic thermal analysis in concrete structure with random material parameters are given.
W artykule zastosowano metodę stochastycznych różnic skończonych do analizy problemów przepływu ciepła i ruchu wilgoci. Przedstawiono sformułowanie teoretyczne problemu. Badano porowatą strukturę z losowymi parametrami materiałowymi. Do rozwiązania zagadnienia zastosowano metodę perturbacyjną.
Źródło:
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo; 2016, 22 (172); 171-183
0860-7214
Pojawia się w:
Zeszyty Naukowe Politechniki Częstochowskiej. Budownictwo
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The analysis of heat fluxes from a loaded elbow joint using thermal imaging
Analiza strumieni ciepła otrzymanych z obrazów termowizyjnych pochodzących z obciążonego stawu łokciowego
Autorzy:
Rusowicz, A.
Piwnik, J.
Powiązania:
https://bibliotekanauki.pl/articles/271347.pdf
Data publikacji:
2016
Wydawca:
Centralny Ośrodek Badawczo-Rozwojowy Aparatury Badawczej i Dydaktycznej, COBRABiD
Tematy:
elbow joint
infrared imaging
heat and mass transfer
staw łokciowy
obraz w podczerwieni
wymiana ciepła i masy
Opis:
The paper presents thermal images of an elbow joint area after it was loaded with three series of 40 push ups. The rises in the skin surface temperature were analysed, and measurement points on four sides of the joint were selected. The temperature rises were determined along with the reasons why they occurred in these points. Then the heat and mass transfer model was described, and the energy balance of the heat given off by the skin surface was made.
Przedstawiono obrazy termowizyjne powierzchni łokcia po tym, jak został obciążony trzema seriami 40 pompek. Wybrano punkty pomiarowe dla czterech stron stawu łokciowego i przeanalizowano w nich wzrosty temperatury powierzchni skóry. Wzrosty temperatury wyznaczono wraz z uzasadnieniem, dlaczego wystąpiły w tych punktach. Następnie opisano model wymiany ciepła i masy oraz wykonano bilans energii ciepła oddawanego przez powierzchnię skóry.
Źródło:
Aparatura Badawcza i Dydaktyczna; 2016, 21, 3; 121-126
2392-1765
Pojawia się w:
Aparatura Badawcza i Dydaktyczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Soret and Dufour effects on MHD free convective flow past a vertical porous plate in the presence of heat generation
Autorzy:
Reddy, G. V. R.
Powiązania:
https://bibliotekanauki.pl/articles/264624.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
promieniowanie
wymiana ciepła
wymiana masy
tarcie
radiation
heat and mass transfer
skin-friction
Nusselt number
Sherwood number
Opis:
An MHD fluid flow is examined over a vertical plate in the presence of Dufour and Soret effects. The resulting momentum, energy and concentration equations are then made similar by introducing the usual similarity transformations. These similar equations are then solved numerically using the Runge-Kutta fourth order method with shooting technique. The effects of various parameters on the dimensionless velocity, temperature and concentration profiles as well as the local values of the skin-friction coefficient, the Nusselt number and Sherwood number are displayed graphically and in a tabular form. A comparison with previously published work is obtained and an excellent agreement is found.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 3; 649-665
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of chemical reaction on magneto-micropolar fluid flow from a radiative surface with variable permeability
Autorzy:
Sharma, B. K.
Singh, A. P.
Yadav, K.
Chaudhary, R. C.
Powiązania:
https://bibliotekanauki.pl/articles/264925.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
reakcja chemiczna
płyn mikropolarny
magnetohydrodynamika
wymiana ciepła
chemical reaction
micropolar fluid
microrotation
magnetohydrodynamics
heat and mass transfer
Opis:
This paper presents a study of a hydromagnetic free convection flow of an electrically conducting micropolar fluid past a vertical plate through a porous medium with a heat source, taking into account the homogeneous chemical reaction of first order. A uniform magnetic field has also been considered in the study which acts perpendicular to the porous surface of the above plate. The analysis has been done by assuming varying permeability of the medium and the Rosseland approximation has been used to describe the radiative heat flux in the energy equation. Numerical results are presented graphically in the form of velocity, micro- rotation, concentration and temperature profiles, the skin-friction coefficient, the couple stress coefficient, the rate of heat and mass transfers at the wall for different material parameters. The study clearly demonstrates how a chemical reaction influences the above parameters under given conditions.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 833-851
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heat and mass transfer in a second grade fluid over a stretching vertical surface in a porous medium
Autorzy:
Baoku, I. G.
Onifade, Y. S.
Adebayo, L. O.
Yusuff, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/265587.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
heat and mass transfer
second grade fluid
porous medium
stretching surface
wymiana ciepła
wymiana masy
materiały porowate
Opis:
The investigation deals with the combined heat and mass transfer in a mixed convection boundary layer flow over a stretching vertical surface in a porous medium filled with a viscoelastic second grade fluid. The partial differential equations governing the model have been transformed by a similarity transformation and the system of coupled-ordinary differential equations is solved by employing the shooting method with the fifth-order Runge-Kutta-Fehlberg iteration technique. Effects of various values of physical parameters embedded in the flow model on the dimensionless velocity, temperature and concentration distributions are discussed and shown with the aid of graphs. Numerical values of physical quantities, such as the local skin-coefficient, local Nusselt number and local Sherwood number are presented in a tabular form. It is observed that the boundary layer fluid velocity increases as the second grade parameter, mixed convection parameter and Prandtl number increase.
Źródło:
International Journal of Applied Mechanics and Engineering; 2015, 20, 2; 239-255
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiative flow past a parabolic started isothermal vertical plate with uniform mass diffusion
Autorzy:
Muthucumaraswamy, R.
Lakshmi, V.
Powiązania:
https://bibliotekanauki.pl/articles/955181.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
promieniowanie
izoterma
płyta pionowa
wymiana ciepła
wymiana masy
parabolic
radiation
isothermal
vertical plate
heat and mass transfer
Opis:
A theoretical solution of thermal radiation effects on an unsteady flow past a parabolic starting motion of an infinite isothermal vertical plate with uniform mass diffusion has been studied. The plate temperature as well as the concentration level near the plate are raised uniformly. The dimensionless governing equations are solved using the Laplace-transform technique. The fluid considered here is a gray, absorbing-emitting radiation but a non-scattering medium. The effects of velocity profiles are studied for different physical parameters such as the thermal radiation parameter, thermal Grashof number, mass Grashof number and Schmidt number. It is observed that the velocity increases with increasing values the thermal Grashof number or mass Grashof number. The trend is just reversed with respect to the thermal radiation parameter.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 1; 195-202
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption-desorption processes in adsorption chillers
Proces adsorpcji i desorpcji w agregacie adsorpcyjnym
Autorzy:
Gwadera, M.
Powiązania:
https://bibliotekanauki.pl/articles/93996.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
adsorption chillers
heat and mass transfer enhancement
mathematical modeling
agregat adsorpcyjny
ulepszenie przepływu ciepła i masy
modelowanie matematyczne
Opis:
The aim of this paper is to present the adsorption chillers technology. The operating principle of these systems, the adsorbent-adsorbate pairs that are frequently applied and the enhancement techniques that allow improvement of their efficiency are presented. Analysis of the mass transfer and principles of mathematical modeling of such systems are also discussed. In the further part of the text, the results of experimental studies and comparison of these results with calculations based on the mathematical model of adsorption were presented.
Niniejsza praca ma na celu zaprezentowanie technologii agregatów adsorpcyjnych. Przedstawiono zasadę działania takich systemów, a mianowicie par adsorbat-adsorbent, które są często stosowane oraz technik ulepszania, które pozwalają na poprawę ich wydajności. Przedyskutowano także analizę przepływu masy oraz zasad modelowania matematycznego takich systemów. W dalszej części przedstawiono wyniki badań eksperymentalnych oraz porównanie takich wyników z obliczeniami na podstawie modelu matematycznego adsorpcji.
Źródło:
Agricultural Engineering; 2016, 20, 2; 81-89
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of chemical reaction and radiation on double diffusive flow of a viscous, dissipative fluid through porous medium in a rectangular cavity with heat sources
Autorzy:
Raju, T. L.
Muralidhar, P.
Powiązania:
https://bibliotekanauki.pl/articles/955281.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
wymiana ciepła
wymiana masy
promieniowanie
rozproszenie
źródło ciepła
heat and mass transfer flow
radiation
dissipation
heat sources
rectangular cavity
porous medium
Opis:
In this paper, an attempt is made to discuss the combined influence of radiation and dissipation on the convective heat and mass transfer flow of a viscous fluid through a porous medium in a rectangular cavity using the Darcy model. Making use of the incompressibility, the governing non-linear coupled equations for the momentum, energy and diffusion are derived in terms of the non-dimensional stream function, temperature and concentration. The Galerkin finite element analysis with linear triangular elements is used to obtain the global stiffness matrices for the values of stream function, temperature and concentration. These coupled matrices are solved using an iterative procedure and expressions for the stream function, temperature and concentration are obtained as linear combinations of the shape functions. The behavior of temperature, concentration, the Nusselt number and Sherwood number is discussed computationally for different values of the governing parameters, such as the Rayleigh Number (Ra), heat source parameter (α), Eckert number (Ec), Schmidt Number (Sc), Soret parameter (S0), buoyancy ratio (N).
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 4; 1115-1150
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of radiation and Eckert number on MHD flow with heat transfer rate near a stagnation point over a non-linear vertical stretching sheet
Autorzy:
Fenuga, O. J.
Hassan, A. R.
Olanrewaju, P. O.
Powiązania:
https://bibliotekanauki.pl/articles/264652.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ magnetohydrodynamiczny
transfer ciepła
transfer masy
liczba Eckerta
MHD flow
heat and mass transfer
radiation
Eckert number stagnation–point
non-linear vertical stretching sheet
Opis:
This work investigates the effects of radiation and Eckert number on an MHD flow with heat transfer rate near a stagnation-point region over a nonlinear vertical stretching sheet. Using a similarity transformation, the governing equations are transformed into a system of ordinary differential equations which are solved numerically using the sixth order Runge-Kutta method with shooting technique. Tabular and graphical results are provided to examine the physical nature of the problem. Heat transfer rate at the surface decreases with radiation, Eckert number and as radiation increases, the flow temperature also increases for velocity ratio parameters […].
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 1; 27-36
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods of Thermal Calculations for a Condensing Waste-Heat Exchanger
Autorzy:
Rączka, P.
Wójs, K.
Powiązania:
https://bibliotekanauki.pl/articles/185363.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
odzysk ciepła kondensacji
obliczanie transferu ciepła i masy
wymiennik ciepła
ciepło odpadowe
condensation heat recovery
calculation of heat and mass transfer
heat exchanger
waste heat
Opis:
The paper presents the algorithms for a flue gas/water waste-heat exchanger with and without condensation of water vapour contained in flue gas with experimental validation of theoretical results. The algorithms were used for calculations of the area of a heat exchanger using waste heat from a pulverised brown coal fired steam boiler operating in a power unit with a capacity of 900 MWe. In calculation of the condensing part, the calculation results obtained with two algorithms were compared (Colburn-Hobler and VDI algorithms). The VDI algorithm allowed to take into account the condensation of water vapour for flue gas temperatures above the temperature of the water dew point. Thanks to this, it was possible to calculate more accurately the required heat transfer area, which resulted in its reduction by 19 %. In addition, the influence of the mass transfer on the heat transfer area was taken into account, which contributed to a further reduction in the calculated size of the heat exchanger - in total by 28% as compared with the Colburn-Hobler algorithm. The presented VDI algorithm was used to design a 312 kW pilot-scale condensing heat exchanger installed in PGE Belchatow power plant. Obtained experimental results are in a good agreement with calculated values.
Źródło:
Chemical and Process Engineering; 2014, 35, 4; 447-461
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of slip velocity in a magneto-micropolar fluid flow from a radiative surface with variable permeability: a numerical study
Autorzy:
Sharma, B. K.
Tailor, V.
Goyal, M.
Powiązania:
https://bibliotekanauki.pl/articles/265273.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
slip velocity
chemical reaction
micropolar fluid
MHD
heat and mass transfer
FDM
poślizg
reakcja chemiczna
płyn mikropolarny
magnetohydrodynamika
przenoszenie ciepła
Opis:
An analysis is presented to describe the hydromagnetic mixed convection flow of an electrically conducting micropolar fluid past a vertical plate through a porous medium with radiation and slip flow regime. A uniform magnetic field has been considered in the study which absorbs the micropolar fluid with a varying suction velocity and acts perpendicular to the porous surface of the above plate. The governing non-linear partial differential equations have been transformed into linear partial differential equations, which are solved numerically by applying the explicit finite difference method. The numerical results are presented graphically in the form of velocity, micro-rotation, concentration and temperature profiles, the skin-friction coefficient, the couple stress coefficient, the rate of heat and mass transfers at the wall for different material parameters.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 3; 637-651
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Closed form solutions of heat and mass transfer in the flow of a MHD visco-elastic fluid over a porous stretching sheet
Autorzy:
Ashokkunar, K.
Veena, P. H.
Pravin, V. K.
Powiązania:
https://bibliotekanauki.pl/articles/955325.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przenoszenie ciepła
przenoszenie masy
magnetohydrodynamika
rozciąganie
płyn lepkoplastyczny
heat and mass transfer
MHD flow
porous stretching sheet
visco-elastic fluid
Opis:
The problem of heat and mass transfer in a visco-elastic fluid flow over a stretching sheet in the presence of a uniform magnetic field is examined. The important physical quantities such as the skin friction coefficient, heat transfer co-efficient and the mass transfer co-efficient are determined. It is found that the heat and mass transfer distribution decreases with the increasing values of the visco-elastic parameter k1.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 4; 989-1002
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Walidacja modelu przepływu ciepła i wilgoci przez ubiór ochronny
Validation of Heat and Mass Transfer Model in the Protective Clothing
Autorzy:
Łapka, P.
Furmański, P.
Bugaj, M. A.
Cieślikiewicz, Ł.
Pietrak, K.
Kubiś, M.
Wiśniewski, T. S.
Powiązania:
https://bibliotekanauki.pl/articles/136466.pdf
Data publikacji:
2016
Wydawca:
Szkoła Główna Służby Pożarniczej
Tematy:
model numeryczny
promieniowanie cieplne
wymiana ciepła i masy
ubranie ochronne
numerical model
thermal radiation
heat and mass transfer
protective clothing
Opis:
W artykule przedstawiono zaawansowany model matematyczny i numeryczny transportu ciepła i masy w wielowarstwowych ubraniach ochronnych, które były poddane działaniu wysokiej temperatury otoczenia lub dużych radiacyjnych strumieni ciepła emitowanych przez gorące ciała. Zaproponowany model uwzględniał przewodzenie ciepła i promieniowanie cieplne w warstwach tkaniny o spektralnych właściwościach optycznych i w szczelinach powietrznych oraz transport energii związany z dyfuzją wilgoci przez ubranie ochronne oraz z procesami sorpcji i desorpcji wody w włóknach tkaniny. Dodatkowo do modelu włączono złożone warunki bilansu energii i masy oraz warunki optyczne na granicach warstw tkaniny. Do rozwiązania równań modelowych opracowano autorski iteracyjny algorytm numeryczny, który bazował na metodzie objętości kontrolnych. Następnie przeprowadzono analizę walidacyjną zaproponowanego modelu obliczeniowego poprzez porównanie otrzymanych wyników z wynikami pomiarów eksperymentalnych dla wybranego pakietu ubrania ochronnego ogrzewanego przez krótki czas radiacyjnym strumieniem ciepła emitowanym przez promiennik podczerwieni, a następnie chłodzonego w otoczeniu. Otrzymano dobrą zgodność czasowych przebiegów temperatury, co potwierdziło wiarygodność zaproponowanego modelu.
An advanced mathematical and numerical model of heat and mass transfer in the multi-layer protective clothing, which was exposed to either high temperature environment or to high incident radiative heat flux emitted by hot objects was presented in this paper. The developed model accounted for heat conduction and thermal radiation in a non -grey layers of the protective garment. Additionally, heat transport associated with water vapour diffusion through the protective clothing and with sorption and desorption of liquid water in the fabric fibres were included. Complex energy and mass balances as well as optical conditions at the external and internal interfaces between clothing layers were formulated and incorporated into the model. A novel iterative numerical algorithm which was based on the Finite Volume Method was developed to solve the system of governing equations. Finally, the validation analysis of the model was carried out for selected multi-layer clothing which was exposed for a short time to radiative heat flux emitted by an infrared emitter and then cooled down in the surroundings. The simulated and experimentally measured time variations of temperatures were in good agreement, therefore the accuracy of the proposed model was validated.
Źródło:
Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej; 2016, 2, 58; 231-251
0239-5223
Pojawia się w:
Zeszyty Naukowe SGSP / Szkoła Główna Służby Pożarniczej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of magnetohydrodynamic (MHD) nanofluid flow with heat and mass transfer over a porous stretching sheet
Autorzy:
Odesola, A. S.
Abiala, I. O.
Akinpelu, F. O.
Fenuga, O. J.
Powiązania:
https://bibliotekanauki.pl/articles/1839771.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
metoda elementów skończonych
wymiana ciepła
wymiana masy
magnetohydrodynamika
finite element method
heat and mass transfer
MHD
nanofluid flow
porous stretching sheet
Opis:
This work investigates a three-dimensional Magnetohydrodynamic (MHD) nanofluid flow with heat and mass transfer over a porous stretching sheet. Firstly, partial differential equations are transformed into coupled non-linear ordinary differential equations through a similarity variables transformation and solved by Galerkin Finite Element Methods (FEM). The effects of thermal radiation, viscous dissipation and chemical reaction on the fluid flow are considered. The behaviour and properties of pertinent flow parameters on the velocity, temperature and concentration profiles are presented and discussed graphically. The effects of the friction coefficient parameter, Nusselt and Sherhood numbers are also shown and considered using tables. The work is in good agreement in comparison with the recent work in literature.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 4; 162-174
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radiation and chemical reaction effects on MHD flow along a moving vertical porous plate
Autorzy:
Reddy, G. V. R.
Reddy, N. B.
Gorla, R. S. R.
Powiązania:
https://bibliotekanauki.pl/articles/265207.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
magnetohydrodynamika
porowatość
promieniowanie cieplne
wymiana ciepła
wymiana masy
reakcja chemiczna
MHD
porous medium
thermal radiation
heat and mass transfer
chemical reaction
Opis:
This paper presents an analysis of the effects of magnetohydrodynamic force and buoyancy on convective heat and mass transfer flow past a moving vertical porous plate in the presence of thermal radiation and chemical reaction. The governing partial differential equations are reduced to a system of self-similar equations using the similarity transformations. The resultant equations are then solved numerically using the fourth order Runge-Kutta method along with the shooting technique. The results are obtained for the velocity, temperature, concentration, skin-friction, Nusselt number and Sherwood number. The effects of various parameters on flow variables are illustrated graphically, and the physical aspects of the problem are discussed.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 1; 157-168
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research methods in the study of heat transfer coefficient during flow in minichannels
Autorzy:
Tychanicz-Kwiecień, Maria
Grosicki, Sebastian
Powiązania:
https://bibliotekanauki.pl/articles/1819147.pdf
Data publikacji:
2021
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
heat transfer coefficient
minichannels
heat and mass transfer analogy
limiting current technique
thermal balance method
współczynnik przenikania ciepła
minikanały
analogia wymiany ciepła i masy
prąd graniczny
bilans cieplny
Opis:
The paper presents the specification of research methods commonly encountered in the studies of heat transfer processes in minichannels. In particular the following methods have been emphasized: electrochemical limiting current method as well as the thermal balance method. In thermal balance method the mean heat transfer coefficient is determined by the set of experimental thermal measurements of the investigated heat exchanger. In turn, limiting current method is based on heat and mass transfer analogy. The discussed research methods have been implemented on two specially designed and constructed test facilities with compact minichannel heat exchangers, which have been presented and described in details. In order to validate the designed setup, the preliminary experimental measurements of two minichannel heat exchangers with hydraulic diameter of 2 mm and rectangular cross sections during single-phase liquid flows have been carried out. In further perspective it is planned to extend the experimental studies of minichannel heat exchangers and to compare the results obtained by both methods described.
Źródło:
Journal of Mechanical and Energy Engineering; 2021, 5, 1; 59--68
2544-0780
2544-1671
Pojawia się w:
Journal of Mechanical and Energy Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ parametrów procesowych na wymianę masy i ciepła podczas adsorpcji wody na silikażelu
The effect of process paramaters on mass and heat transfer during adsorption of water on silica gel
Autorzy:
Gwadera, M.
Powiązania:
https://bibliotekanauki.pl/articles/134835.pdf
Data publikacji:
2015
Wydawca:
ADVSEO
Tematy:
adsorpcja
żel krzemionkowy
woda
chłodzenie adsorpcyjne
poprawa transferu ciepła i masy
adsorption
silica gel
water
adsorption chilling
heat and mass transfer enhancement
Opis:
This paper presents the results of studies on the enhancement of heat and mass transfer in an adsorber which is the main element of an adsorption chiller. A silica gel/water adsorption pair was examined. Experimental studies that refer to adsorption dynamics in a layer of silica gel covering directly the heat exchanger pipe were performed. Adsorption was conducted under different process conditions. Gas flow rate and size of grains were changed. Breakthrough curves and temperature changes with time were determined.
Źródło:
Technical Issues; 2015, 3; 25-32
2392-3954
Pojawia się w:
Technical Issues
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methodology for experimental research of heat and mass transfer processes during inhalation of e-cigarettes aerosols
Metodyka badań doświadczalnych procesów wymiany ciepła i masy w procesie inhalacji aerozolu z e-papierosów
Autorzy:
Odziomek, M.
Powiązania:
https://bibliotekanauki.pl/articles/2073337.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
electronic cigarette
aerosol
humidity
droplet size distribution
heat and mass transfer
elektroniczny papieros
aerozol
wilgotność
rozkład wielkości kropel
wymiana ciepła i masy
Opis:
This work is focused on the development and validation of experimental method for testing EC-aerosols under simulated conditions of human respiratory tract with variable aerosol residence time in the physiologically humid environment associated with the inhalation pattern. Initial results obtained using the laser diffractometry indicate the usefulness and applicability of developed method for EC-aerosol testing for a deeper understanding of simultaneous heat and mass transfer processes during EC-aerosol formation, inhalation and movement in the human respiratory tract.
Praca koncentruje się na opracowaniu i walidacji metodyki badań doświadczalnych aerozoli uwalnianych z e-papierosów do środowiska odzwierciedlającego pod względem panującej wilgotności, temperatury oraz czasu przebywania aerozolu drogi oddechowe człowieka. Wstępne wyniki uzyskane przy użyciu dyfraktometru laserowego wskazują na przydatność zaproponowanej metody badania aerozoli do głębszego zrozumienia roli procesów wymiany ciepła oraz masy w trybie ich powstawania, inhalacji oraz transportu w drogach oddechowych.
Źródło:
Inżynieria i Aparatura Chemiczna; 2018, 5; 144--145
0368-0827
Pojawia się w:
Inżynieria i Aparatura Chemiczna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hydromagnetic flow past an exponentially accelerated isothermal vertical plate with uniform mass diffusion in the presence of chemical reaction of first order
Autorzy:
Muthucumaraswamy, R.
Valliammal, V.
Powiązania:
https://bibliotekanauki.pl/articles/265196.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
płyta pionowa
wymiana ciepła
wymiana masy
reakcja chemiczna
pole magnetyczne
accelerated
isothermal
vertical plate
exponential
heat and mass transfer
chemical reaction
magnetic field
Opis:
An exact solution of an unsteady flow past an exponentially accelerated infinite isothermal vertical plate with uniform mass diffusion in the presence of a transverse magnetic field has been studied. The plate temperature is raised to Tw and the species concentration level near the plate is also made to rise Cʹw . The dimensionless governing equations are solved using the Laplace-transform technique. The velocity, temperature and concentration profiles are studied for different physical parameters such as the magnetic field parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number, time and a. It is observed that the velocity decreases with increasing the magnetic field parameter.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 1; 259-267
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theoretical study of heat transfer effects on flow past a parabolic started vertical plate in the presence of chemical reaction of first order
Autorzy:
Muthucumaraswamy, R.
Velmurugan, S.
Powiązania:
https://bibliotekanauki.pl/articles/955128.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
reakcja chemiczna
płyta pionowa
wymiana masy
wymiana ciepła
transformata Laplace'a
parabolic
homogeneous
chemical reaction
first order
vertical plate
heat and mass transfer
Opis:
An exact solution of an unsteady flow past a parabolic starting motion of an infinite vertical plate with variable temperature and mass diffusion, in the presence of a homogeneous chemical reaction of first order has been studied. The plate temperature as well as concentration level near the plate are raised linearly with time t. The dimensionless governing equations are solved using the Laplace-transform technique. The effects of velocity profiles are studied for different physical parameters such as the chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number and time. It is observed that the velocity increases with increasing values of the thermal Grashof number or mass Grashof number. The trend is just reversed with respect to the chemical reaction parameter.
Źródło:
International Journal of Applied Mechanics and Engineering; 2014, 19, 2; 275-284
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The four-sided lid driven square cavity using stream function-vorticity formulation
Autorzy:
Bagai, Shobha
Kumar, Manoj
Patel, Arvind
Powiązania:
https://bibliotekanauki.pl/articles/1839818.pdf
Data publikacji:
2020
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
four-sided lid-driven square cavity
heat and mass transfer
ADI
isotherms
concentration contours
przepływ
izotermy
transfer ciepła
transfer masy
liczba Reynoldsa
liczba Prandtla
liczba Schmidta
metoda ADI
Alternating Direction Implicit
Opis:
In this paper, an unsteady 2-D incompressible fluid flow with heat and mass transfer in a four-sided lid driven square cavity is investigated numerically. The top, bottom, left, and right walls of the square cavity move to the right, left, downward and upward respectively. All four sides of the cavity move with a uniform velocity. The flow variables are simulated below the critical Reynolds numbers with isothermal and mass-transfer conditions in the square cavity. We have used a streamfunction-vorticity (ψ - ξ) formulation to investigate the fluid flow in terms of flow variables ψ, ξ, T and C at low Reynolds numbers (Re). The Prandtl number (Pr) and Schmidt number (Sc) have been chosen as 6:62 and 10, 50, 100, 150 respectively, in order to calculate the numerical solutions of T and C. The matrix method has been used to evaluate the stability and convergence of the numerical scheme. The conditions obtained from the matrix method have been used to arrive at the numerical solutions with desired accuracy.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2020, 19, 2; 17-30
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A numerical method for viscous flow in a driven cavity with heat and concentration sources placed on its side wall
Autorzy:
Ambethkar, V.
Basumatary, L. R.
Powiązania:
https://bibliotekanauki.pl/articles/122794.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
numerical method
viscous flow
heat source
concentration source
driven square cavity
general algorithm
stability conditions
isotherms
streamlines
geometric center
heat and mass transfer
metoda numeryczna
lepki przepływ
źródło ciepła
warunki stabilności
izotermy
transfer ciepła
transfer masy
Opis:
This paper proposes a method to numerically study viscous incompressible two-dimensional steady flow in a driven square cavity with heat and concentration sources placed on its side wall. The method proposed here is based on streamfunction-vorticity (Ψ-ξ) formulation. We have modified this formulation in such a way that it suits to solve the continuity, x and y-momentum, energy and mass transfer equations which are the governing equations of the problem under investigation in this study. No-slip and slip wall boundary conditions for velocity, temperature and concentration are defined on walls of a driven square cavity. In order to numerically compute the streamfunction Ψ, vorticityfunction ξ , temperature θ, concentration C and pressure P at different low, moderate and high Reynolds numbers, a general algorithm was proposed. The sequence of steps involved in this general algorithm are executed in a computer code, developed and run in a C compiler. We propose that, with the help of this code, one can easily compute the numerical solutions of the flow variables such as velocity, pressure, temperature, concentration, streamfunction, vorticityfunction and thereby depict and analyze streamlines, vortex lines, isotherms and isobars, in the driven square cavity for low, moderate and high Reynolds numbers. We have chosen suitable Prandtl and Schmidt numbers that enables us to define the average Nusselt and Sherwood numbers to study the heat ad mass transfer rates from the left wall of the cavity. The stability criterion of the numerical method used for solving the Poisson, vorticity transportation, energy and mass transfer has been given. Based on this criterion, we ought to choose appropriate time and space steps in numerical computations and thereby, we may obtain the desired accurate numerical solutions. The nature of the steady state solutions of the flow variables along the horizontal and vertical lines through the geometric center of the square cavity has been discussed and analyzed. To check the validity of the computer code used and corresponding numerical solutions of the flow variables obtained from this study, we have to compare these with established steady state solutions existing in the literature and they have to be found in good agreement.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 3; 17-30
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Agitation efficiency of different physical systems
Autorzy:
Karcz, Joanna
Szoplik, Jolanta
Major-Godlewska, Marta
Cudak, Magdalena
Kiełbus-Rąpała, Anna
Powiązania:
https://bibliotekanauki.pl/articles/2086781.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
agitated vessel
power consumption
mixing time
heat and mass transfer
gas hold-up
wzburzony statek
pobór energii
czas mieszania
wymiana ciepła i masy
zatrzymywanie gazu
Opis:
Efficiency of agitation was considered for different physical systems on the basis of our own experimental studies on homogenisation, heat and mass transfer as well as gas hold-up. Measurements were performed for different physical systems: Newtonian liquids of low and higher viscosity, pseudoplastic liquid, gas–liquid and gas–solid–liquid systems agitated in vessels of the working volume from 0.02 m3 to 0.2 m3. Agitated vessels of different design were equipped with a high-speed impeller (10 impellers were tested). Comparative analysis of the experimental results proved that energy inputs (power consumption) should be taken into account as a very important factor when agitation efficiency is evaluated in order to select a proper type of equipment. When this factor is neglected in the analysis, intensification of the process can be estimated only.
Źródło:
Chemical and Process Engineering; 2021, 42, 2; 139--156
0208-6425
2300-1925
Pojawia się w:
Chemical and Process Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Entropy increase as a measure of energy degradation in heat transfer
Autorzy:
Drożyński, Z.
Powiązania:
https://bibliotekanauki.pl/articles/240672.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
second law of thermodynamics in heat
heat and mass transfer
entropy increment
surface heat exchangers
Clausius-Rankine cycle
druga zasada termodynamiki w ogniu
wymiana ciepła i masy
przyrost entropii
obieg Clausiusa-Rankine'a
Opis:
Heat transfer is an irreversible process. This article defines the entropy increment as a measure of energy degradation in heat transfer realized in typical surface heat exchangers. As an example of the proposed entropy increase method, presented below are the calculations for heat exchangers working in a typical Clausius-Rankine cycle. The entropy increase in such exchangers inevitably leads to increased fuel consumption and, as a further consequence, to increased carbon dioxide emission.
Źródło:
Archives of Thermodynamics; 2013, 34, 3; 147-161
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady three-dimensional MHD flow due to impulsive motion with heat and mass transfer past a stretching sheet in a saturated porous medium
Autorzy:
Rajagopal, K.
Veena, P. H.
Pravin, V. K.
Powiązania:
https://bibliotekanauki.pl/articles/264376.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
przepływ laminarny
naprężenia ścinające
wymiana ciepła
wymiana masy
unsteadiness
laminar flow
three dimensional
shear stress
heat and mass transfer
short-time and long-time solution
Opis:
The development of velocity, temperature and concentration fields of an incompressible viscous electrically conducting fluid, caused by impulsive stretching of the surface in two lateral directions and by suddenly increasing the surface temperature from that of the surrounding fluid in a saturated porous medium is studied. The partial differential equations governing the unsteady laminar boundary layer flow are solved analytically. For some particular cases, closed form solutions are obtained, and for large values of the independent variable asymptotic solutions are found. The surface shear stress in x and y directions and the surface heat transfer and surface mass transfer increase with the magnetic parameter and with permeability parameter and the stretching ratio, and there is a smooth transition from the short-time solution to the long-time solution.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 1; 137-151
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chemical reaction effects on MHD flow past a linearly accelerated vertical plate with variable temperature and mass diffusion in the presence of thermal radiation
Autorzy:
Muthucumaraswamy, R.
Geetha, E.
Powiązania:
https://bibliotekanauki.pl/articles/264827.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
izotermiczność
promieniowanie
płyta pionowa
wymiana masy
wymiana ciepła
pole magnetyczne
reakcja chemiczna
accelerated
isothermal
radiation
vertical plate
heat and mass transfer
magnetic field
chemical reaction
Opis:
An exact solution of first order chemical reaction effects on a radiative flow past a linearly accelerated infinite isothermal vertical plate with variable mass diffusion, under the action of a transversely applied magnetic field has been presented. The plate temperature is raised linearly with time and the concentration level near the plate is also raised to C'w linearly with time. The dimensionless governing equations are tackled using the Laplace-transform technique. The velocity, temperature and concentration fields are studied for different physical parameters such as the magnetic field parameter, radiation parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number, Prandtl number and time. It is observed that velocity increases with decreasing magnetic field parameter or radiation parameter. But the trend is just reversed with respect to the chemical reaction parameter.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 727-737
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential of Indirect Regenerative Evaporative Cooling System (M-Cycle) for Electronic Applications
Możliwości zastosowania systemu IREC (pracującego w cyklu M) do chłodzenia układów elektronicznych
Autorzy:
Olbrycht, Robert
Kałuża, Marcin
Felczak, Mariusz
Levchenko, Dmytro
Więcek, Bogusław
Powiązania:
https://bibliotekanauki.pl/articles/27312463.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
evaporative cooling
porous materials
capillary materials
heat and mass transfer
IR thermography
chłodzenie wyparne
materiały porowate
materiały kapilarne
wymiana ciepła i masy
termografia w podczerwieni
Opis:
The article presents a simple prototype system based on the concept of indirect regenerative evaporative cooling (IREC) thermodynamic cycle for electronics applications. The key problem of selecting porous capillary material is discussed and preliminary experimental results are presented using IR thermography. The presented research is an initial step towards the development of a laboratory-validated, fully operational IREC system for high-power electronics.
W artykule przedstawiono prototypowy układ chłodzenia oparty na koncepcji cyklu termodynamicznego pośredniego regeneracyjnego chłodzenia wyparnego (IREC) do zastosowań w elektronice. Omówiono kluczowy problem doboru porowatego materiału kapilarnego i przedstawiono wstępne wyniki eksperymentów z wykorzystaniem termografii w podczerwieni. Przedstawione badania stanowią wstępny krok w kierunku opracowania zweryfikowanego laboratoryjnie, w pełni funkcjonalnego systemu IREC do odprowadzania ciepła w systemach elektronicznych dużej mocy.
Źródło:
Pomiary Automatyka Robotyka; 2023, 27, 3; 19--25
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Axisymmetric mixed convective MHD flow over a slender cylinder in the presence of chemically reaction
Autorzy:
Prasad, K. V.
Vaidya, H.
Vajravelu, K.
Datti, P. S.
Umesh, V.
Powiązania:
https://bibliotekanauki.pl/articles/264807.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
pole magnetyczne
reakcja chemiczna
przepływ konwekcyjny
metoda Keller-box
Keller-box method
Grashof number
slender cylinder
convective flow
magnetic field
chemical reaction
heat and mass transfer
Opis:
The present analysis is focused on the study of the magnetic effect on coupled heat and mass transfer by mixed convection boundary layer flow over a slender cylinder in the presence of a chemical reaction. The buoyancy effect due to thermal diffusion and species diffusion is investigated. Employing suitable similarity transformations, the governing equations are transformed into a system of coupled non-linear ordinary differential equations and are solved numerically via the implicit, iterative, second order finite difference method. The numerical results obtained are compared with the available results in the literature for some special cases and the results are found to be in excellent agreement. The velocity, temperature, and the concentration profiles are presented graphically and analyzed for several sets of the pertinent parameters. The pooled effect of the thermal and mass Grashof number is to enhance the velocity and is quite the opposite for temperature and the concentration fields.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 1; 121-141
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of heat and mass transfer in an adsorption bed using CFD methods
Autorzy:
Janusz, Szymon
Szudarek, Maciej
Rudniak, Leszek
Borcuch, Marcin
Powiązania:
https://bibliotekanauki.pl/articles/27312232.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
heat transfer
adsorption
CFD
mass transfer
refrigeration devices
Opis:
The trend of reducing electricity consumption and environmental protection has contributed to the development of refrigeration technologies based on the thermal effect of adsorption. This article proposes a methodology for conducting numerical simulations of the adsorption and desorption processes. Experimental data available in the literature were used as guidelines for building and verifying the model, and the calculations were carried out using commercial computational fluid dynamics software. The simulation results determined the amount of water vapor absorbed by the adsorbent bed and the heat generated during the adsorption process. Throughout the adsorption process, the inlet water vapor velocity, temperature, and pressure in the adsorbent bed were monitored and recorded. The results obtained were consistent with the theory in the literature and will serve as the basis for further, independent experimental studies. The validated model allowed for the analysis of the effect of cooling water temperature on the sorption capacity of the material and the effect of heating water temperature on bed regeneration. The proposed approach can be useful in analyzing adsorption processes in refrigeration applications and designing heat and mass exchangers used in adsorption systems.
Źródło:
Archives of Thermodynamics; 2023, 44, 2; 177--194
1231-0956
2083-6023
Pojawia się w:
Archives of Thermodynamics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Unsteady MHD thermal diffusive and radiative fluid flow past a vertical porous plate with chemical reaction in slip flow regime
Autorzy:
Ravi Kumar, D.
Jayarami Reddy, K.
Raju, M. C.
Powiązania:
https://bibliotekanauki.pl/articles/265452.pdf
Data publikacji:
2019
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
swobodna konwekcja
magnetohydrodynamika
przenoszenie ciepła
dyfuzja termiczna
promieniowanie
reakcja chemiczna
poślizg
MHD
free convection
heat and mass transfer
slip flow regime
thermal diffusion
radiation
chemical reaction
Opis:
An analytical solution of an MHD free convective thermal diffusive flow of a viscous, incompressible, electrically conducting and heat-absorbing fluid past a infinite vertical permeable porous plate in the presence of radiation and chemical reaction is presented. The flow is considered under the influence of a magnetic field applied normal to the flow. The plate is assumed to move with a constant velocity in the direction of fluid flow in slip flow regime, while free stream velocity is assumed to follow the exponentially increasing small perturbation law. The velocity, temperature, concentration, skin friction, Nusselt number and Sherwood number distributions are derived and have shown through graphs and tables by using the simple perturbation technique.
Źródło:
International Journal of Applied Mechanics and Engineering; 2019, 24, 1; 117-129
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of casting technology of the pressure die cast AZ91D Mg-based alloy
Optymalizacja technologii ciśnieniowego odlewu ze stopu Mg-AZ91D
Autorzy:
Piwowarski, G.
Krajewski, W. K.
Lelito, J.
Powiązania:
https://bibliotekanauki.pl/articles/264033.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
odlewanie pod ciśnieniem
odlewane stopy Mg
symulacja numeryczna
wymiana ciepła i masy
porowatość
pressure die casting
Mg-base cast alloys
numerical simulation
heat and mass transfer
porosity
Opis:
Pressure die casting has become the next area of experimentation on virtual models in computer memory. The article presents an attempt to optimize the manufacturing process of an item made of magnesium AZ91D alloy, which was cast using the pressure technology on a machine with a hot pressing chamber. Special attention was paid to the flow velocity in individual parts of the gating system and in the mould cavity, as well as to the air evacuation from the mould cavity. The aim was to achieve a flawless casting, especially in terms of porosity.
Odlewnictwo ciśnieniowe stało się kolejnym obszarem objętym możliwością przeprowadzania eksperymentów wirtualnych za pomocą komputerów. W artykule przedstawiono próbę optymalizacji procesu wytwarzania elementu wykonanego ze stopu magnezu AZ91D, który odlewany był w technologii odlewania ciśnieniowego w urządzeniu z gorąca komorą prasowania. Szczególną uwagę zwrócono na prędkość przepływu w poszczególnych elementach układu wlewowego i w przestrzeni wnęki formy, jak również na ewakuację powietrza z wnęki formy. Nadrzędnym celem pracy było uzyskanie odlewu bez wad wewnętrznych, ze szczególnym wskazaniem na porowatość.
Źródło:
Metallurgy and Foundry Engineering; 2010, 36, 2; 105-111
1230-2325
2300-8377
Pojawia się w:
Metallurgy and Foundry Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiz i modelirovanie teploobmennykh ustrojjstv v kontaktnykh apparatakh
Analysis and simulation of heat exchange devices in the contact devices
Autorzy:
Spinov, V.
Powiązania:
https://bibliotekanauki.pl/articles/77965.pdf
Data publikacji:
2014
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
heat exchange
contact
mass transfer
heat transfer
contact device
energy efficiency
mathematical model
Źródło:
Motrol. Motoryzacja i Energetyka Rolnictwa; 2014, 16, 5
1730-8658
Pojawia się w:
Motrol. Motoryzacja i Energetyka Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The improvement of the rheological model for controlling the stress-strain state and humidity in the materials of museum pieces: zener thermodiffusion model for capillary-porous bodies
Autorzy:
Dovhaliuk, V. B.
Chovnyuk, Y. V.
Ivanov, E. A.
Shyshyna, M. O.
Powiązania:
https://bibliotekanauki.pl/articles/114762.pdf
Data publikacji:
2019
Wydawca:
Stowarzyszenie Menedżerów Jakości i Produkcji
Tematy:
aftereffect
colloid capillary-porous bodies
deformations
heat and mass transfer
Ishlinskiy - Rzhanitsin generalized rheological model of the elastic-viscous body
Zener thermodiffusion rheological model
model reologiczny
model termodyfuzji Zenera
ciało kapilarno-porowate
transfer ciepła
transfer masy
Opis:
The drying and humidifying processes of capillary-porous (colloid) bodies occur during the production of various materials for the consumer goods industry, building materials, storage of museum pieces, etc. It is known that the main linkage forms of the moisture and colloid capillary-porous bodies (CCPBs), namely adsorption, capillary condensation and capillary linkage of the free moisture in the cavities of the above bodies, depend on the temperature and relative humidity of drying/humidifying agent. It means that the CCPBs behave in a peculiar way depending on the temperature and humidity fields. The problems of CCPBs drying (or humidifying) process include the issue of the heat and humidity transfer both in the middle of the body and in the boundary layer on the interface of phases “body (object of drying/humidifying process) – environment”. The drying/humidifying intensity is at its maximum when the possibilities of the heat and mass transfer in the boundary layer correspond to the possibilities of moisture and heat moving inside the object of drying/humidifying process. The properties of the CCPB as material possessing specific elastic-viscous properties are described within the framework of O.Y. Ishlinskiy - O.R. Rzhanitsin generalized elastic-viscous body theory. A comparative analysis of the above mentioned CCPB’s properties from the point of view of Zener thermodiffusion theory is conducted. The mechanism of moisture transferring from the CCPBs’ central layers (as object of drying/humidifying process) up to their surfaces is developed. The theoretical researches examined the drying/humidifying phenomena for both the entire volume of the CCPB and three structural directions. It is noted that drying/humidifying of CCPBs is a complicated heat and mass transfer process accompanied by mechanisms of molecular nature determining the kinetics of their running. It is shown that the appropriate equations’ solution of molecular-molar heat and moisture transfer under the appropriate boundary (limit) conditions allows to describe the fields, i.e. the distribution of transfer potentials (the temperature and moisture content in the CCPB as object of drying/humidifying) at any time of the appropriate process. The drying/humidifying curves (“drying/humidifying rate versus CCPB humidity”) and the temperature curves (“CCPB temperatures versus CCPB humidity”) reflect the nature of the drying/humidifying processes. In the framework of the proposed generalized rheological model of CCPB, the residual deformations of bodies for various load types (the time-varying stress applied to the CCPB) is estimated.
Źródło:
Zeszyty Naukowe. Quality. Production. Improvement; 2019, 2 (11); 51-71
2544-2813
Pojawia się w:
Zeszyty Naukowe. Quality. Production. Improvement
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical modeling of heat and mass transfer process under heat treatment of grain materials in dense layer
Matematicheskoe modelirovanie teplomassoobmennykh processov pri termoobrabotke zernovykh materialov v plotnom sloe
Autorzy:
Kotov, B.
Kalinichenko, R.
Spirin, A.
Powiązania:
https://bibliotekanauki.pl/articles/792105.pdf
Data publikacji:
2016
Wydawca:
Komisja Motoryzacji i Energetyki Rolnictwa
Tematy:
mass transfer
heat transfer
grain
harvesting process
heat treatment
mathematical modelling
temperature field
moisture content
Źródło:
Teka Komisji Motoryzacji i Energetyki Rolnictwa; 2016, 16, 4
1641-7739
Pojawia się w:
Teka Komisji Motoryzacji i Energetyki Rolnictwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the Specific Heat Flux During Boiling of the Dispersed Phase of the Emulsion
Autorzy:
Pavlenkо, Anatoliy
Koshlak, Hanna
Basok, Borys
Hrabova, Tatiana
Powiązania:
https://bibliotekanauki.pl/articles/27315739.pdf
Data publikacji:
2023
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
steam explosion
homogenisation
boiling
intensification of heat
mass transfer
Opis:
The intensity of heat exchange between the boiling emulsion and the enclosing surfaces is associated with the physical phenomena of the formation, growth, and destruction of vapour bubbles of the low-boiling component in the liquid phase. This article presents a methodology to assess the intensity of heat exchange processes. Using this technique, it is possible to predict the energy parameters of heat exchange equipment and the degree of intensification of heat transfer processes.
Źródło:
Rocznik Ochrona Środowiska; 2023, 25; 16--24
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Matematyczny model procesów wymiany ciepła i masy w przeciwprądowym osuszaczu powietrza
Mathematical model of heat and mass transfer in an counterflow air dehumidifier
Autorzy:
Anisimov, S.
Kowalski, P.
Powiązania:
https://bibliotekanauki.pl/articles/237640.pdf
Data publikacji:
2008
Wydawca:
Polskie Zrzeszenie Inżynierów i Techników Sanitarnych
Tematy:
wymiana ciepła
wymiana masy
modelowanie
osuszacz sorpcyjny
mass transfer
heat transfer
modeling
dehumidifier
Opis:
W pracy przeanalizowano proces wspólnej wymiany ciepła i masy zachodzący w obrotowych osuszaczach powietrza w układach klimatyzacyjnych. Na podstawie przeprowadzonej analizy (proces wymiany masy zachodzi w kierunku przeciwnym dodatniej różnicy ciśnień cząstkowych) uzasadniono zastosowanie potencjału chemicznego do opisu nieustalonych procesów wymiany masy w wypełnieniu osuszacza. Wykazano, że w obrotowym osuszaczu powietrza tworzy się obraz tzw. kombinowanej fali, charakteryzujący się powstaniem dwóch stref aktywnej wymiany ciepła i masy. W ramach przyjętych założeń przedstawiono i uzasadniono model matematyczny (?-model). Przedstawiono także wyniki obliczeń fali termicznej i adsorpcyjnej uzyskane na podstawie opracowanego modelu. Wykazano, że analiza procesów zachodzących w strefach aktywnej wymiany ciepła i masy umożliwia oszacowanie zakresu zmian optymalnych roboczych parametrów osuszacza, jak również ocenę możliwości jego racjonalnego wykorzystania.
The process of coupled heat and mass transfer that occurs in a rotary dehumidifier used in air conditioning systems was made subject to analysis, and the results obtained (the mass transfer process occurs in the direction opposite to the positive water vapor partial pressure difference) have justified the application of the chemical potential to the description of the nonsteady-state processes of mass transfer in the dehumidifier matrix. It has been demonstrated that an image of the so-called combined wave arises in the rotary dehumidifier of air, and that the image is characterized by the formation of two active zones of heat and mass transfer. Within the framework of the assumptions made, the relevant mathematical model (?-model) was developed and substantiated, and the calculated values of the thermal and adsorption waves obtained with the model were presented. It has been found that the analysis of the processes arising in the active zones of heat and mass transfer made it possible to assess the range of changes in the optimal operating parameters of the dehumidifier, as well as the range of rational uses where the dehumidifier could be applied.
Źródło:
Ochrona Środowiska; 2008, 30, 4; 49-51
1230-6169
Pojawia się w:
Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł

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