可压缩层流边界层中扰动波诱发小激波的机理研究

项目名称： 可压缩层流边界层中扰动波诱发小激波的机理研究

项目编号： No.10872018

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 袁湘江

作者单位： 北京航空航天大学

项目金额： 48万元

中文摘要： 在一些可压缩流动中有小激波存在，其特殊的耗散机制,对层流转捩和湍流发展具有重要影响。系统研究小激波现象，对揭示可压缩层流转捩机制、湍流演化规律和探索流动控制方法等都具有重要意义。针对可压缩湍流和自由剪切层中的小激波现象，已进行了较为充分的讨论。而始于上世纪末可压缩边界层中小激波现象研究还很少，目前只是利用DNS，大体上确定了它的存在和了解了部分特征。已有研究表明，边界层中小激波的发生发展机理与湍流和自由剪切层有很大差异。围绕边界层小激波还有很多问题没有明确，如小激波的形成条件和触发机理？边界层与静止大气中形成小激波的机制有无差异？边界层中的TS波能否直接触发小激波？边界层中小激波的形态和位置？粘性对小激波的形成和演化的影响等。本项目的研究内容是首先从波动学的理论入手，讨论上述小激波现象的理论问题。其次发展数值模拟方法，检验理论研究的正确性，拓宽理论研究的范围，验证Coleman等人的预言。

中文关键词： 小激波；理论分析；数值模拟；TS波；波动

英文摘要： In compressible flows, the unique dissipation mechanism significantly influences the transition process and the development of turbulence. The research on the shocklets is of great importance on discovering the transition mechanism in compressible flow, the rule of turbulence development and flow structures. In contrast, investigations on the shocklets appear more in compressible isotropic turbulent flows and free shear flows. While, the study on shocklets in compressible boundary layers was firstly started in 1990s, and the mechanism of occurrence and development differs greatly from that in turbulent flows and free shear flows. In fact, with the aid of DNS, the occurring possibility and some characteristics of shocklets in supersonic boundary layers can be discovered; whereas a lot more theoretical problems about this phenomenon need to be discussed and solved. Such as, what is the formation condition and occurring mechanism; is there any differences on the formation of shocklets between in boundary layers and in still air; is it possible that the T-S wave in boundary layers triggers the shocklets and determines the configuration of shocklets; what is the role of viscosity on the formation and development of shocklets etc. The present research starts with the wave theory and discusses the theoretical problems mentioned above. Then numerical simulation is developed to verify the validity of theoretical research. Meanwhile, the theoretical analysis is extended to affirm the threshold value predicted by Coleman et al.

英文关键词： shocklets; theoretical analysis; numerical simulation; wave theory; T-S wave