scholarly journals Impact of using triple adiabatic obstacles on natural convection inside porous cavity under non-darcy flow and local thermal non-equilibrium model

2021 ◽  
pp. 105760
Author(s):  
Anwar Ahmed Yousif ◽  
Omar Rafae Alomar ◽  
Asmaa Taha Hussein
Keyword(s):  
Natural Convection ◽  
Equilibrium Model ◽  
Darcy Flow ◽  
Porous Cavity ◽  
Non Equilibrium

Unsteady natural convection in a partially porous cavity having a heat-generating source using local thermal non-equilibrium model

2019 ◽  
Vol 29 (6) ◽  
pp. 1902-1919 ◽  
Author(s):  
Marina S. Astanina ◽  
Mikhail Sheremet ◽  
C. Jawali Umavathi
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Porous Layer ◽  
Equilibrium Model ◽  
Local Heat ◽  
Darcy Number ◽  
Content Type ◽  
Porous Cavity ◽  
Variation Parameter ◽  
Non Equilibrium

Purpose The purpose of this study is a numerical analysis of transient natural convection in a square partially porous cavity with a heat-generating and heat-conducting element using the local thermal non-equilibrium model under the effect of cooling from the vertical walls. It should be noted that this research deals with a development of passive cooling system for the electronic devices. Design/methodology/approach The domain of interest is a square cavity with a porous layer and a heat-generating element. The vertical walls of the cavity are kept at constant cooling temperature, while the horizontal walls are adiabatic. The heat-generating solid element is located on the bottom wall. A porous layer is placed under the clear fluid layer. The governing equations, formulated in dimensionless stream function, vorticity and temperature variables with corresponding initial and boundary conditions, are solved using implicit finite difference schemes of the second order accuracy. The governing parameters are the Darcy number, viscosity variation parameter, porous layer height and dimensionless time. The effects of varying these parameters on the average total Nusselt number along the heat source surface, the average temperature of the heater, the fluid flow rate inside the cavity and on the streamlines and isotherms are analyzed. Findings The results show that in the case of local thermal non-equilibrium the total average Nusselt number is an increasing function of the interphase heat transfer coefficient and the porous layer thickness, while the average heat source temperature decreases with the Darcy number and viscosity variation parameter. Originality/value An efficient numerical technique has been developed to solve this problem. The originality of this work is to analyze unsteady natural convection within a partially porous cavity using the local thermal non-equilibrium model in the presence of a local heat-generating solid element. The results would benefit scientists and engineers to become familiar with the analysis of convective heat transfer in enclosures with local heat-generating heaters and porous layers, and the way to predict the heat transfer rate in advanced technical systems, in industrial sectors including transportation, power generation, chemical sectors and electronics.

A thermal non-equilibrium model for predicting LNG boil-off in storage tanks incorporating the natural convection effect

Energy ◽  
2021 ◽  
pp. 121162
Author(s):  
Zhongdi Duan ◽  
Hongxiang Xue ◽  
Xueru Gong ◽  
Wenyong Tang
Keyword(s):  
Natural Convection ◽  
Equilibrium Model ◽  
Storage Tanks ◽  
Non Equilibrium

Numerical analysis of convection conduction and radiation using a non-equilibrium model in a square porous cavity

2007 ◽  
Vol 46 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Irfan Anjum Badruddin ◽  
Z.A. Zainal ◽  
P.A. Aswatha Narayana ◽  
K.N. Seetharamu
Keyword(s):  
Numerical Analysis ◽  
Equilibrium Model ◽  
Porous Cavity ◽  
Non Equilibrium
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