Open Access
ARTICLE
ENTROPY GENERATION DUE TO NATURAL CONVECTION WITH NON -UNIFORM HEATING OF POROUS QUADRANTAL ENCLOSURE-A NUMERICAL STUDY
Shantanu Dutta*
, Arup Kumar Biswas
Department of Mechanical Engineering, National Institute of Technology, Durgapur-713209, INDIA
* Corresponding Author: Email: .
Frontiers in Heat and Mass Transfer 2018, 10, 1-12. https://doi.org/10.5098/hmt.10.8
Abstract
Industrial processes optimization for higher energy efficiency may be effectively carried out based on the thermodynamic approach of entropy
generation minimization (EGM). This approach provides the key insights on how the available energy (exergy) is being destroyed during the process
and the ways to minimize its destruction. In this study, EGM approach is implemented for the analysis of optimal thermal mixing and temperature
uniformity due to natural convection in quadrantal cavity filled with porous medium for the material processing applications or for cooling of electrical
equipments. Effect of the permeability of the porous medium and the role of non-uniform heating in enhancing the thermal mixing, temperature effects
and minimization of entropy generation is analyzed. The numerical solutions are obtained using finite element method. Stream lines , Isotherms and
Entropy generation results are depicted for Ra=10
6, 1.7x10
5
, 10
4 and for Da=10
-3, 10
-4 and 10
-5 at Pr=0.71.It is found that at lower Darcy number
(Da), the thermal mixing is low and the heat transfer irreversibility dominates the total entropy generation. In contrast, thermal mixing is improved due
to enhanced convection at higher Da. It is observed that fluid friction irreversibility dominates over heat transfer irreversibility for only Da=10
-3 at
Ra=10
6. The local entropy generation is maximum at the bottom wall, while at the center and top of the enclosure it becomes minimum. Based on EGM
analysis, it is established that total entropy production is not significant with larger thermal mixing at high Darcy number, and can be recommended
for material processing process or for cooling of electrical equipments.
Keywords
Cite This Article
Dutta, S. (2018). ENTROPY GENERATION DUE TO NATURAL CONVECTION WITH NON -UNIFORM HEATING OF POROUS QUADRANTAL ENCLOSURE-A NUMERICAL STUDY.
Frontiers in Heat and Mass Transfer, 10(1), 1–12.