Similarity of ideal gas flow at different scales

作     者：王沫然 李志信 

作者机构：Department of Engineering Mechanics Tsinghua University Beijing 100084 China 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2003年第46卷第6期

页      面：661-670页

核心收录：

学科分类：080704[工学-流体机械及工程] 080103[工学-流体力学] 08[工学] 0807[工学-动力工程及工程热物理] 0801[工学-力学（可授工学、理学学位）] 

基　　金：This work was supported by the State Key Lab of Applied Optics Changchun Institute of Optics and Fine Mechanics and Physics and Joint Academy of Nankai Universityand Tianjin University 

主　　题：similarity, ideal gas flow, direct simulation Monte Carlo. 

摘      要：The similarity of ideal gas flow at different scales is investigated analytically and nu-merically. With the compressible and rarefied effects considered, two dimensionless parameters, Mach number and Knudsen number, are proposed as the similarity criterions, because the Rey-nolds number can be expressed by the Mach number and the Knudsen number of ideal gases. A DSMC method is used to simulate flows at different scales with the same Ma and Kn, including subsonic channel flows and the supersonic flows over a hot plate. Comparisons between the re-sults of different scales show that the normalized fields of macroscopic quantities are the same. This confirms the similarity. Especially, the results indicate that the micro flow are similar to the rarefied flow of ideal gas, which suggests that many transformations are available from the existing rarefied flow results to the micro flow.