scholarly journals Numerical Study of Thermophoresis on Mass Transfer from Natural Convection Flow over a Vertical Porous Medium with Variable Wall Heat Fluxes

2021 ◽  
Vol 11 (21) ◽  
pp. 10418
Author(s):  
Jian-Sheng Huang
Keyword(s):  
Mass Transfer ◽  
Porous Medium ◽  
Natural Convection ◽  
Numerical Solutions ◽  
Gas Diffusion ◽  
Heat Fluxes ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Variable Wall ◽  
Buoyancy Ratio

This study investigates heat and mass transfer under natural convection flow along a vertical permeable surface with variable wall heat fluxes through a porous medium. The non-Darcian model is employed for the medium. The effects of suction/blowing, inertia, buoyancy ratio, exponent of heat flux, position parameter, Schmidt number, and thermophoresis are considered. The governing equations of continuity, momentum, energy, and concentration are solved by adopting similarity transformation and Runge–Kutta integration with a shooting technique. Results of interest, such as velocity, temperature, and concentration profiles related to local Nusselt and Sherwood numbers, are obtained for the selected buoyancy ratio at different magnitudes of the thermophoretic effect. The numerical solutions help us to realize the gas diffusion phenomena and control the transport technology.

scholarly journals MHD natural convection flow of Casson fluid in an annular microchannel containing porous medium with heat generation/absorption

2020 ◽  
Vol 9 (1) ◽  
pp. 223-232 ◽  
Author(s):  
B.J. Gireesha ◽  
S. Sindhu
Keyword(s):  
Porous Medium ◽  
Natural Convection ◽  
Skin Friction ◽  
Interaction Parameter ◽  
Heat Generation ◽  
Velocity Slip ◽  
Casson Fluid ◽  
Convection Flow ◽  
Natural Convection Flow ◽  
Wall Interaction

AbstractThis study has been conducted to focus on natural convection flow of Casson fluid through an annular microchannel formed by two cylinders in the presence of magnetic field. The process of heat generation/absorption is taken into consideration. Combined effects of various parameters such as porous medium, velocity slip and temperature jump are considered. Solution of the present mathematical model is obtained numerically using fourth-fifth order Runge-Kutta-Fehlberg method. The flow velocity, thermal field, skin friction and Nusselt number are scrutinized with respect to the involved parameters of interest such as fluid wall interaction parameter, rarefaction parameter, Casson parameter and Darcy number with the aid of graphs. It is established that higher values of Casson parameter increases the skin friction coefficient. Further it is obtained that rate of heat transfer diminishes as fluid wall interaction parameter increases.

Integral Methods in Natural-Convection Flow

1955 ◽  
Vol 22 (4) ◽  
pp. 515-522
Author(s):  
Salomon Levy
Keyword(s):  
Natural Convection ◽  
Horizontal Cylinder ◽  
Convection Flow ◽  
Inclined Plate ◽  
Natural Convection Flow ◽  
Specific Flow ◽  
Integral Methods ◽  
Method Of Solution ◽  
Arbitrary Body ◽  
Variable Wall

Abstract This paper presents an evaluation of the range of application, accuracy, and usefulness of integral methods in natural-convection flow. The study reveals (a) that integral methods may be utilized to obtain approximate answers to free-convection problems whenever exact analytical solutions become too involved. Specific-flow examples considered here (natural convection from inclined plate, horizontal cylinder, arbitrary body, or within enclosed channels) confirm their adaptability to complicated configurations. (b) Over-all accuracy of the solutions is good. For inclined plates the derived equations reduce at high Grashof numbers to the correlation proposed and verified by Rich (1) while in the case of horizontal cylinders the results compare satisfactorily with the theoretical values of Hermann (2) and the accepted experimental relations (12). (c) The integral method of solution may be extended to apply to low Prandtl number fluids, laminar or turbulent flow, variable wall temperature, and convection within confined spaces.

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