壁面小折角对马赫数4.5边界层中扰动演化的影响  

Evolution of disturbances in boundary layer for Mach number 4.5 over a small angle of wall corner

作　　者：吴宁宁[1] 罗纪生[1] 

机构地区：[1]天津大学力学系,天津300072

出　　处：《空气动力学学报》2014年第2期219-227,共9页Acta Aerodynamica Sinica

基　　金：国家重点基础研究发展计划(2009CB724103);国家自然科学基金项目(11172204)

摘　　要：为了利用e N方法预测带小折角平板边界层的转捩,采用数值模拟和流动稳定性方法研究来流马赫数为4.5,扩张角和压缩角分别为1°、2°、3°的高超声速边界层中扰动的演化,得到不同角度下不同频率的扰动波沿流向的幅值及增长率分布。并对工程中常用的预测带小折角平板转捩位置的e N方法进行验证分析,指出采用e N方法预测带小折角平板转捩时需要对N值进行修正的概念。In order to predict the boundary layer transition over small wall corner using e N method,numerical simulations and linear stability theory method are carried out to investigate the disturbance evolutions in hypersonic boundary layers for the cases where the expansion and compression angles are 1°,2°,3°respectively with Mach number 4.5by solving the classic O-S equation（LST）and N-S equation（DNS）.The amplitude and growth rate distribution along the flow direction with different frequencies in different angles have been revealed.Meanwhile,a new disturbance was excited when the disturbance evolutions in hypersonic boundary layers for the small expansion wall corner.Based on these findings,the Nvalue should be corrected in the scenario to predict the transition location with a small wall corner by using the e Nmethod combined with stability analysis,and a correction factor of Nvalue was presented in this work.

关 键 词：扩张角 压缩角 转捩 e N方法 中性曲线 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]