Effect of Richardson number on entropy generation over backward facing step

Sheng CHEN

doi:10.1007/s10483-012-1637-8

Applied Mathematics and Mechanics >

2012 , Vol. 33 >Issue 11: 1431 - 1440

DOI: https://doi.org/10.1007/s10483-012-1637-8

Articles

Effect of Richardson number on entropy generation over backward facing step

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1. Research & Development Center, Wuhan Iron and Steel Corporation (WISCO), Wuhan 430083, P. R. China;
2. State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology, Wuhan 430074, P. R. China

Received date: 2011-11-17

Revised date: 2012-05-05

Online published: 2012-11-10

Supported by

Project supported by the National Natural Science Foundation of China (Nos. 51176061 and 51006043), the Research Foundation for Outstanding Young Teachers of Huazhong University of Science and Technology (No. 2012QN168), and the Research Fund for the Doctoral Program of Higher Education of China (No. 20100142120048)

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Abstract

The flow over a backward facing step (BFS) has been taken as a useful prototype to investigate intrinsic mechanisms of separated flow with heat transfer. However, to date, the open literature on the effect of Richardson number on entropy generation over the BFS is absent yet, although the flow pattern and heat transfer characteristic both will receive significant influence caused by the variation of Richardson number in many practical applications, such as in microelectromechanical systems and aerocrafts. The effect of Richardson number on entropy generation in the BFS flow is reported in this paper for the first time. The entropy generation analysis is conducted through numerically solving the entropy generation equation. The velocity and temperature, which are the inputs of the entropy generation equation, are evaluated by the lattice Boltzmann method. It is found that the distributions of local entropy generation number and Bejan number are significantly influenced by the variation of Richardson number. The total entropy generation number is a monotonic decreasing function of Richardson number, whereas the average Bejan number is a monotonic increasing function of Richardson number.

Key words： entropy generation; backward facing step; Richardson number; lattice Boltzmann method; coincidence theorems; the best approximation; contractible space; composites of acyclic mappings

Cite this article

Sheng CHEN . Effect of Richardson number on entropy generation over backward facing step[J]. Applied Mathematics and Mechanics, 2012 , 33(11) : 1431 -1440 . DOI: 10.1007/s10483-012-1637-8

References

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