Pore Scale Numerical Investigation of Mixed Convection From an Isolated Heat Source in a Channel With a Porous Insert

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Vijayalakshmi Yerramalle ◽  
B. Premachandran ◽  
Prabal Talukdar
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Porous Medium ◽  
Heat Source ◽  
Mixed Convection ◽  
Numerical Simulations ◽  
Circular Cylinders ◽  
Channel Height ◽  
Heater Surface ◽  
Pore Scale

Abstract Mixed convection heat transfer in a channel filled with porous medium and containing an isolated heat source at the bottom wall is studied in this work. The porous medium is assumed to be made of circular cylinders and is placed only on the heater surface. Three different configurations of porous medium are considered in this study. Pore-scale numerical simulations are carried out using the exact geometry of porous medium. The same configuration is also investigated using the volume-averaged approximation. The temperature distribution of the heater surface obtained from the pore-scale numerical simulation is compared with the results obtained from the volume-averaged numerical simulation. Parametric studies are carried out by varying the material of the cylinders, the porosity, and the height of the porous medium. The effects of Grashof number and Reynolds number of the flow are also studied as part of this investigation. The results obtained from the pore-scale numerical simulations show that the presence of the porous medium leads to reduction in heat transfer, while the results obtained from the volume-averaged numerical simulations show an enhancement of heat transfer due to the presence of the porous medium on the heater surface. However, the pore-scale numerical simulation results show that the heat transfer enhancement is only possible if the channel height is completely filled with the selected porous medium.

scholarly journals Heat source and sink effects on periodic mixed convection flow along the electrically conducting cone inserted in porous medium

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0260845
Author(s):  
Asifa Ilya ◽  
Muhammad Ashraf ◽  
Aamir Ali ◽  
Zahir Shah ◽  
Poom Kumam ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Heat Transfer ◽  
Porous Medium ◽  
Finite Difference ◽  
Heat Source ◽  
Prandtl Number ◽  
Mixed Convection ◽  
Current Density ◽  
Electrically Conducting ◽  
Source And Sink

The system of partial differential equations governing the unsteady hydromagnetic boundary-layer flow along an electrically conducting cone embedded in porous medium in the presence of thermal buoyancy, magnetic field, heat source and sink effects are formulated. These equations are solved numerically by using an implicit Finite-Difference Method. The effects of the various parameters that are source/sink parameter, porous medium parameter, Prandtl number, mixed convection parameter and magnetic Prandtl number on the velocity, temperature profiles, transverse magnetic field are predicted. The effects of heat source and sink parameter on the time-mean value as well as on transient skin friction; heat transfer and current density rate are delineated especially in each plot. The extensive results reveal the existence of periodicity and show that periodicity becomes more distinctive for source and sink in the case of the electrically conducting cone. As the source and sink contrast increases, the periodic convective motion is invigorated to the amplitude and phase angle as reflect in the each plot. The dimensionless forms of the set of partial differential equations is transform into primitive form by using primitive variable formulation and then are solved numerically by using Finite Difference Scheme which has given in literature frequently. Physical interpretations of the overall flow and heat transfer along with current density are highlighted with detail in results and discussion section. The main novelty of the obtained numerical results is that first we retain numerical results for steady part and then used in unsteady part to obtain transient skin friction, rate of heat transfer and current density. The intensity of velocity profile is increased for increasing values of porosity parameter Ω, the temperature and mass concentration intensities are reduced due heat source effects.

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