跨克努森数区域的微通道内流动计算模拟研究  

Investigations of micro-channel flows across Knudsen flow regime

作　　者：张根烜[1] 袁智[1] 张先锋[1] 

机构地区：[1]中国电子科技集团公司第三十八研究所,安徽合肥230031

出　　处：《热科学与技术》2017年第1期52-58,共7页Journal of Thermal Science and Technology

摘　　要：采用一阶和修正二阶的滑移连续介质模型,对跨克努森数区域的低速微通道流进行二维和三维数值模拟。用实验结果和DSMC方法验证滑移连续介质模型在跨克努森数区域中的适用性,并详细讨论了微通道流的可压缩效应、稀薄效应、低雷诺数效应和三维特性。研究表明,克努森数是表征稀薄效应和模型适用性的特征参数,滑移连续介质模型适用于克努森数小于0.150的氮气流动;马赫数不再是微通道流可压缩效应的唯一标识参数;雷诺数是表征低雷诺数效应和三维特性的关键参数,高宽比大于20的微通道流具备良好的二维特性。The two-dimensional and three-dimensional modeling are performed to investigate the low Mach number gaseous flows in micro-channels using the first order and the alternative second order continuum-based slip models,respectively.The validityof the slip models is examined by the corresponding experiments and the DSMC method under different Knudsen numbers.Moreover,the compressibility effect,rarefaction effect,low Reynolds number effect and three-dimensional characteristics of the micro-channel flows are discussed in detail.Simulations show that the Knudsen number is a key parameter to determine the magnitude of rarefaction effect and the validity of slip models.The present continuum-based slip models have alsobeen demonstrated to be appropriate for micro-channel nitrogen flows with Kn 〈 0.15.The Mach number is not the unique parameter to govern the compressibility effect of micro-channel flows.The Reynolds number is the key parameter to represent the low Reynolds number effect and three-dimensional characteristics.The results have shown that the micro-channel flows with the height to width ratio in excess of 20,have a good 2D characteristic.

关 键 词：微通道 克努森数 雷诺数 滑移模型 

分 类 号：O354[理学—流体力学] V211[理学—力学]