Effect of Richardson number on entropy generation over backward facing step
Effect of Richardson number on entropy generation over backward facing step
复制标题
理查森数对后向步骤熵产生的影响
DOI：
10.1007/s10483-012-1637-8
复制
发表时间：
2012
影响因子：
--
通讯作者：
Sheng Chen
中科院分区：
文献类型：
--
作者：
Sheng Chen
向后台阶 (BFS) 上的流动已被用作研究分离流与传热的内在机制的有用原型。然而，迄今为止，尽管在许多实际应用中，例如在微机电系统和航空器中，理查森数的变化都会对流型和传热特性产生重大影响，但迄今为止，还没有关于理查森数对BFS熵产生影响的公开文献。本文首次报道了BFS流中理查森数对熵产生的影响。熵产生分析是通过数值求解熵产生方程来进行的。速度和温度是熵生成方程的输入，通过格子玻尔兹曼方法进行评估。研究发现局部熵生成数和Bejan数的分布受Richardson数的变化影响显着。总熵生成数是理查森数的单调递减函数，而平均贝詹数是理查森数的单调递增函数。
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.