Heat‐flux‐specified boundary treatment for gas flow and heat transfer in microchannel using direct simulation Monte Carlo method
Heat‐flux‐specified boundary treatment for gas flow and heat transfer in microchannel using direct simulation Monte Carlo method
复制标题
使用直接模拟蒙特卡罗方法对微通道中气体流动和传热进行热通量指定边界处理
DOI：
10.1002/nme.2203
复制
发表时间：
2008
影响因子：
2.9
通讯作者：
Q. He
中科院分区：
文献类型：
--
作者：
Qiuwan Wang;Xiao;Q. He
直接模拟蒙特卡罗(DSMC)方法已被广泛应用于微流控装置内气体流动与换热的研究。对于与微电子机械系统(MEMS)相关的流动，热通量指定(HFS)边界条件广泛存在。然而，在用DSMC方法模拟微通道流动时，并没有考虑到HFS边界问题。为了解决这一问题，人们提出了一种新的技术--逆温采样(ITS)。这项技术提供了一种根据指定的壁面热流计算分子反射特征温度的方法。ITS技术与DSMC法相结合，可以处理简单气体和混合气体的DSMC法中的HFS边界条件。为验证该方法的有效性，采用壁温特定(WTS)边界条件下的二维Poiseuille流动的热流密度作为新方法的初始热边界条件。用ITS法采集的壁温与预期值吻合较好。比较了两种热边界条件(WTS和HFS)下的压力、速度和温度分布。研究了分子碰撞模型和气面相互作用模型的影响。结果表明，所提出的ITS方法能够较准确地模拟MEMS中的气体流动和换热。版权所有©2007 John Wiley&Sons，Ltd.
Direct simulation Monte Carlo (DSMC) method has been widely used to study gaseous flow and heat transfer in micro‐fluidic devices. For flows associated with microelectromechanical systems (MEMS), the heat‐flux‐specified (HFS) boundary condition broadly exists. However, problems with HFS boundary have not been realized in the simulation of microchannel flows with DSMC method. To overcome this problem, a new technique named as inverse temperature sampling (ITS) is developed. This technique provides an approach to calculate the molecular reflective characteristic temperature from the specified heat flux at the wall boundary. Coupling with DSMC method, the ITS technique can treat the HFS boundary condition in DSMC method for both simple gas and gas mixtures. For validation, heat flux obtained from two‐dimensional Poiseuille flows with wall‐temperature‐specified (WTS) boundary condition is employed as the initial thermal boundary condition of our new method. Sampled wall temperature by the ITS method agrees well with the expected value. Pressure, velocity and temperature distributions under these two thermal boundary conditions (WTS and HFS) are compared. Effects of molecule collision model and gas–surface interaction model are also investigated. Results show that the proposed ITS method could accurately simulate gaseous flow and heat transfer in MEMS. Copyright © 2007 John Wiley & Sons, Ltd.