Analytical and Numerical Study on Thermally Developing Forced Convective Flow in a Channel Filled with a Highly Porous Medium Under Local Thermal Non-Equilibrium

2021 ◽  
Author(s):  
Yuan Yi ◽  
Xiaohui Bai ◽  
Fujio Kuwahara ◽  
Akira Nakayama
Keyword(s):  
Porous Medium ◽  
Convective Flow ◽  
Numerical Study ◽  
Forced Convective Flow ◽  
Highly Porous ◽  
Non Equilibrium

scholarly journals Analysis of MHD Forced Convective Flow of Variable Fluid Properties over a Saturated Porous Medium with Thermal Radiation Effect

2016 ◽  
Vol 9 ◽  
pp. 47-65 ◽  
Author(s):  
Kolawole Sunday Adegbie ◽  
Adeyemi Isaiah Fagbade
Keyword(s):  
Porous Medium ◽  
Heat Loss ◽  
Convective Flow ◽  
Radiative Heat ◽  
Saturated Porous Medium ◽  
Fluid Velocity ◽  
Radiative Heat Loss ◽  
Variable Fluid Properties ◽  
Fluid Properties ◽  
Forced Convective Flow

The present paper addresses the problem of MHD forced convective flow in a fluid saturated porous medium with Brinkman-Forchheimer model, which is an important physical phenomena in engineering applications. The paper extends the previous models to account for effects of variable fluid properties on the forced convective flow through a porous medium in the presence of radiative heat loss using bivariate spectral relaxation method (BSRM). The dynamic viscosity and thermal conductivity of the newtonian fluid are assumed to vary linearly respectively, with temperature whereas the contribution of thermal radiative heat loss is based on Rosseland diffussion approximation. The flow model is described and expressed in form of a highly coupled nonlinear system of partial differential equations. The method of solution BSRM as proposed by Motsa [25] seeks to decouple the original system of PDEs to form a sequence of equations that can be solved in a computationally efficient manner. BSRM is an approach that applies spectral collocation independently in all underlying independent variable is executed to obtain approximate solutions of the problem. The proposed algorithm is supposed to be a very accurate, convergent and very effective in generating numerical results. The results obtained show a significant effects of the flow control parameters on the fluid velocity and temperature respectively. Consequently, the wall shear stress and local heat transfer rate of the present paper are compared with the available results in literatures. Remarkable impacts and a good agreement are found.

Constructal Design of Rectangular Fin Intruded Into Mixed Convective Lid-Driven Cavity Flows

2016 ◽  
Vol 138 (10) ◽  
Author(s):  
G. Lorenzini ◽  
B. S. Machado ◽  
L. A. Isoldi ◽  
E. D. dos Santos ◽  
L. A. O. Rocha
Keyword(s):  
Nusselt Number ◽  
Aspect Ratio ◽  
Convective Flow ◽  
Numerical Study ◽  
Reynolds Numbers ◽  
Lower Surface ◽  
Driven Cavity ◽  
Constructal Design ◽  
Mixed Convective Flow ◽  
Forced Convective Flow

The present work shows a numerical study of laminar, steady, and mixed convective flow inside lid-driven square cavity with intruded rectangular fin in its lower surface. The main purpose here is to maximize the heat transfer between the rectangular fin and the surrounding mixed convective flow inside a lid-driven cavity by means of constructal design. The problem is subject to two constraints, the lid-driven cavity and intruded fin areas. The ratio between the fin and cavity areas is kept fixed (ϕ = 0.05). The investigated geometry has one degree-of-freedom (DOF), the fin aspect ratio (H1/L1), which is varied in the range 0.1 ≤ H1/L1 ≤ 10. The aspect ratio of the cavity is maintained fixed (H/L = 1.0). The effect of the fin geometry over the Nusselt number is investigated for several Rayleigh (RaH = 103, 104, 105 and 106) and Reynolds numbers (ReH = 10, 102, 3.0 × 102, 5.0 × 102, 7.0 × 102 and 103). For all simulations, the Prantdl number is fixed (Pr = 0.71). The conservation equations of mass, momentum, and energy are numerically solved with the finite volume method. Results showed that fin geometry (H1/L1) has strong influence over the Nusselt number in the fin. It was also observed that the effect of H1/L1 over Nusselt number changes considerably for different Rayleigh numbers and for the lowest magnitudes of Reynolds numbers, for example, differences of nearly 770% between RaH = 106 and forced convective flow were observed for the lowest Reynolds number studied (ReH = 10).

scholarly journals Numerical study of magnetohydrodynamic mixed convective flow in a lid-driven enclosure filled with nanofluid saturated porous medium with center heater

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1861-1873
Author(s):  
Thangavelu Mahalakshmi ◽  
Nagarajan Nithyadevi ◽  
Hakan Oztop
Keyword(s):  
Heat Transfer ◽  
Porous Medium ◽  
Fluid Flow ◽  
Convective Flow ◽  
Numerical Study ◽  
Bottom Wall ◽  
Height Velocity ◽  
Flow And Heat Transfer ◽  
Mixed Convective Flow ◽  
Heater Length

This present numerical study explores the MHD mixed convective flow and heat transfer analysis in a square porous enclosure filled with nanofluid having center thin heater. The left and right walls of the enclosure are maintained at temperature T . The bottom wall is c considered with a constant heat source whereas the remaining part of bottom wall and top wall are kept adiabatic. The finite volume method based on SIMPLE algorithm is used to solve the governing equations in order to investigate the effect of heater length, Hartmann, Richardson, and Darcy numbers on the fluid-flow and heat transfer characteristics inside the enclosure. A set of graphical results are presented in terms of streamlines, isotherms, mid height velocity profiles and average Nusselt numbers. The results reveal that heat transfer rate increases as heater length increases for increasing Darcy and Richardson numbers. Among the two positions of heaters, larger enhancement of heat transfer is obtained for horizontal heater of maximum length. It is observed that, Hartmann number is a good control parameter for heat transfer in fluid-flow through porous medium in enclosure. Moreover, Ag-water nanofluid has greater merit to be used for heat transfer enhancement. This problem may be occurred in designing cooling system for electronic equipment to maximize the efficiency with active and secured operational conditions.

scholarly journals Dual solutions for radiative MHD forced convective flow of a nanofluid over a slendering stretching sheet in porous medium

2015 ◽  
Vol 12 (2) ◽  
pp. 115-124 ◽  
Author(s):  
C. Sulochana ◽  
N. Sandeep
Keyword(s):  
Porous Medium ◽  
Differential Equations ◽  
Convective Flow ◽  
Stretching Sheet ◽  
Velocity Slip ◽  
Skin Friction Coefficient ◽  
Dual Solutions ◽  
Navier Slip ◽  
Matlab Package ◽  
Forced Convective Flow

In this study we analyzed the magnetohydrodynamic forced convective flow of a nanofluid over a slendering stretching sheet in porous medium in presence of thermal radiation and slip effects. We presented dual solutions for no-slip and Navier slip conditions. Using self similarity transformation, the governing partial differential equations are transformed into nonlinear ordinary differential equations and solved numerically using bvp5c Matlab package. The effects of dimensionless governing parameters on velocity and temperature profiles of the flow are discussed with the help of graphs. Numerical computations are carried out and discussed for skin friction coefficient and local Nusselt number. We found an excellent agreement of the present results with the existed results under some special conditions. Results indicate that the dual solutions exist only for certain range of velocity slip parameter. It is also found that the heat transfer performance is high in presence of velocity slip effect.

scholarly journals Impacts of Amplitude and Local Thermal Non-Equilibrium Design on Natural Convection within NanoflUid Superposed Wavy Porous Layers

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1277
Author(s):  
Ammar I. Alsabery ◽  
Tahar Tayebi ◽  
Ali S. Abosinnee ◽  
Zehba A. S. Raizah ◽  
Ali J. Chamkha ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Convective Flow ◽  
Numerical Study ◽  
Darcy Number ◽  
Working Fluid ◽  
Free Convective Flow ◽  
Transfer Rates ◽  
Solid Phases ◽  
The Impact ◽  
Non Equilibrium

A numerical study is presented for the thermo-free convection inside a cavity with vertical corrugated walls consisting of a solid part of fixed thickness, a part of porous media filled with a nanofluid, and a third part filled with a nanofluid. Alumina nanoparticle water-based nanofluid is used as a working fluid. The cavity’s wavy vertical surfaces are subjected to various temperature values, hot to the left and cold to the right. In order to generate a free-convective flow, the horizontal walls are kept adiabatic. For the porous medium, the Local Thermal Non-Equilibrium (LTNE) model is used. The method of solving the problem’s governing equations is the Galerkin weighted residual finite elements method. The results report the impact of the active parameters on the thermo-free convective flow and heat transfer features. The obtained results show that the high Darcy number and the porous media’s low modified thermal conductivity ratio have important roles for the local thermal non-equilibrium effects. The heat transfer rates through the nanofluid and solid phases are found to be better for high values of the undulation amplitude, the Darcy number, and the volume fraction of the nanofluid, while a limit in the increase of heat transfer rate through the solid phase with the modified thermal ratio is found, particularly for high values of porosity. Furthermore, as the porosity rises, the nanofluid and solid phases’ heat transfer rates decline for low Darcy numbers and increase for high Darcy numbers.

Sign in / Sign up

Export Citation Format

Share Document