scholarly journals Mathematical Modelling of Radiative Hydromagnetic Thermosolutal Nanofluid Convection Slip Flow in Saturated Porous Media

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Mohammed Jashim Uddin ◽  
Osman Anwar Bég ◽  
Ahmad Izani Md. Ismail
Keyword(s):  
Heat Flux ◽  
Porous Media ◽  
Radiative Heat ◽  
Slip Flow ◽  
Velocity Slip ◽  
Darcy Number ◽  
Radiative Heat Flux ◽  
Force Model ◽  
Radiation Processing ◽  
Convective Boundary

High temperature thermal processing of nanomaterials is an active area of research. Many techniques are being investigated to manipulate properties of nanomaterials for medical implementation. In this paper, we investigate thermal radiation processing of a nanomaterial fluid sheet extruded in porous media. A mathematical model is developed using a Darcy drag force model. Instead of using linear radiative heat flux, the nonlinear radiative heat flux in the Rosseland approximation is taken into account which makes the present study more meaningful and practically useful. Velocity slip and thermal and mass convective boundary conditions are incorporated in the model. The Buongiornio nanofluid model is adopted wherein Brownian motion and thermophoresis effects are present. The boundary layer conservation equations are transformed using appropriate similarity variables and the resulting nonlinear boundary value problem is solved usingMaple 14which uses the Runge-Kutta-Fehlberg fourth fifth order numerical method. Solutions are validated with previous nonmagnetic and nonradiative computations from the literature, demonstrating excellent agreement. The influence of Darcy number, magnetic field parameter, hydrodynamic slip parameter, convection-conduction parameter, convection-diffusion parameter, and conduction-radiation parameter on the dimensionless velocity, temperature, and nanoparticle concentration fields is examined in detail. Interesting patterns of relevance are observed to improve manufacturing of nanofluids.

Numerical Study of Radiative Heat Flux Emitted by Stainless Wire-Net Porous Media

2020 ◽  
Vol 861 ◽  
pp. 509-513
Author(s):  
Niwat Ketchat ◽  
Bundit Krittacom
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Porous Media ◽  
Radiative Heat ◽  
Solid Phase ◽  
Numerical Study ◽  
Convection Heat Transfer ◽  
Radiative Heat Flux ◽  
Air Velocity ◽  
Lower Volume

Numerical model of the convective-radiative heat transfer of porous media was proposed. A stainless wire-net was used as porous media. The physical properties, consisting of porosity (φ) and optical thickness (τ0), of porous media were independent variables. The air velocity was reported in the form of Reynolds number (Re). Two equations of the conservative energy with local thermal non-equilibrium were analyzed. The gas (θf) and solid (θs) phases of conservative energy equation inside porous media were investigated. The radiative heat flux (ψ) at down-stream of solid phase emitted into outside was dealt by the P1 approximation. From the study, it was found that the level of θf and θs decreased as Re increased because the effect of convection heat transfer. Inversely, the level of ψ increased as increasing Re. The level of θf, θs and ψ were decreased as φ increased owing to a lower volume of material depended on the increasing level of φ resulting to the heat transfer rate became lower. The level of θf, θs and ψ gave increased with τ0 becaues a wider distance in absorping energy leading to a higher emission energy from the porous media was achieved.

scholarly journals A numerical study on slip flow in packed hyper-porous media inside micro-channels using differential transformation method

2016 ◽  
Vol 4 (2) ◽  
pp. 57
Author(s):  
Puyan Saffari ◽  
Esmaeel Fatahian ◽  
Peyman Saffari ◽  
Hossein Fatahian
Keyword(s):  
Porous Media ◽  
Gas Flow ◽  
Numerical Study ◽  
Slip Flow ◽  
Velocity Slip ◽  
Darcy Number ◽  
Transformation Method ◽  
Differential Transformation Method ◽  
Differential Transformation ◽  
Micro Channels

Velocity slip boundary condition in parallel-plate micro-channels filled with hyper-porous media is studied using differential transformation method (DTM) in order to find an analytical approximate solution. The results focus on slip flow regime (i.e., for Knudsen numbers in the range 10−3 < Kn < 10−1). The Darcy-Brinkman-Forchheimer model is applied to study the effect of nonlinear drag term further boundary-friction effects on hydrodynamic of gas flow in micro-channels. The results show that DTM results are in good agreement with numerical ones. Also, it is observed that decreasing the value of Darcy number flattens the velocity profile while this trend is opposite for decreasing the Forchheimer number. Also, increasing the value of  causes to increase the velocity slip at the wall.

scholarly journals Non-Similar Solution of G-jitter Induced Unsteady Magnetohydrodynamic Radiative Slip Flow of Nanofluid

2020 ◽  
Vol 10 (4) ◽  
pp. 1420 ◽  
Author(s):  
M.J. Uddin ◽  
W.A. Khan ◽  
O. Anwar Bég ◽  
A. I. M. Ismail
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Radiative Heat ◽  
Free Stream ◽  
Volume Fraction ◽  
Slip Flow ◽  
Velocity Slip ◽  
Flux Boundary Condition ◽  
Transfer Rates ◽  
Special Cases

We present a mathematical model and numerical simulation of the unsteady 2-D g-jitter-free and forced the convective flow of water-based nanofluid from a flat plate, considering both the velocity slip and thermal slip conditions imposed on the wall of the plate. The Darcian model is used, and both cases of a calm and moving free stream are considered. In place of the extensively used linearly varying radiative heat flux, the nonlinearly varying heat flux calculation is applied to produce practically useful results. Further, we incorporate the “zero mass flux boundary condition” which is believed to be more realistic than the earlier extensively used “actively” controlled model. The parameter influences the non-dimensional velocity, temperature, nanoparticle volume fraction, skin friction and heat transfer rates are visualized graphically and discussed in detail. Special cases of the results are benchmarked with those existing in the literature, and a good arrangement is obtained. It is found that the rate of heat transfer is lower for the calm free stream rather than the moving free stream.

Nonequilibrium radiative heat flux modeling for the Huygens entry probe

2006 ◽  
Vol 111 (E7) ◽  
Author(s):  
T. E. Magin ◽  
L. Caillault ◽  
A. Bourdon ◽  
C. O. Laux
Keyword(s):  
Heat Flux ◽  
Radiative Heat ◽  
Radiative Heat Flux ◽  
Entry Probe

Handling of Collimated Irradiation on a Plane-Parallel Participating Medium

2000 ◽  
Author(s):  
Christian Proulx ◽  
Daniel R. Rousse ◽  
Rodolphe Vaillon ◽  
Jean-François Sacadura
Keyword(s):  
Heat Flux ◽  
Monte Carlo ◽  
Monte Carlo Method ◽  
Radiative Heat ◽  
Radiative Heat Flux ◽  
Scattering Media ◽  
One Dimensional ◽  
Plane Parallel ◽  
Collimated Beam ◽  
Good Agreement

Abstract This article presents selected results of a study comparing two procedures for the treatment of collimated irradiation impinging on one boundary of a participating one-dimensional plane-parallel medium. These procedures are implemented in a CVFEM used to calculate the radiative heat flux and source. Both isotropically and anisotropically scattering media are considered. The results presented show that both procedures provide results in good agreement with those obtained using a Monte Carlo method, when the collimated beam impinges normally.

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