小Knudsen数稀薄气体绕流流场分析

本文从Ｂｏｌｔｚｍａｎｎ方程５矩和１３矩方程出发，应用三层模型分析了滑流国稀薄气体绕流流场的性态，提出了一个计算这种流场的完整模型。理论分析表明，摩阻系数的小Ｋｕｎｄｓｅｎ数效应是高除小量，可忽略不计；但必须考虑热传导系数的小Ｋｎｕｄｓｅｎ数效应。基于奇异摄动法分析，数值求解了绕二维平板流动流场，壁面摩阻系数和热流率的计算结果与现有的实验和理论结果相一致。

Analysis the Low Knudsen Number Rarefied Flow Fields

The rarefied flows in the slip field is analysed by Trip-Layer model based upon 5-moment equations and 13-moment equations derived from the Boltzmann's equations. A complete mathematical model to descripe the flow fields is presented.As a theoretical results, low Knudsen number effects on skin-friction coefficient is such a high-order small quantity that it can be ignored, while low Knudsen number effects on heat transfer coefficient must be taken into account. With the help of Singular Perturbation method, numerical solutions for the two-dimensional plate flows are obtained. The calculation results of skin-friction coefficient and heat transfer rate show consistency with other existing experimental or theoretical results.