可压缩轴对称射流流场近区的数值模拟

采用高精度差分方法对二维轴对称可压缩射流流场进行了数值模拟，研究了大尺度涡结构的形成和发展过程及其在射流雪展过程中的作用，计算结果显示了射流失稳后首先出现Ｋｅｌｖｉｎ－Ｈｅｌｍｈｏｌｔｚ非稳定特征，之后向下游发展的过程中， 一笥效应的增长导致涡的配对和对并；指出射流场中压力波动的分布是大尺度涡结构分布的直接结果。

NUMERICAL SIMULATION OF THE NEAR REGION OF COMPRESSIBLE AXISYMMETRIC

The flow fields of 2-D compressible axisymmetric jet are simulated by solving N-S equations. The dis-cretization method has high order accuracy. The information and development of the large vortical structure and it's role in the jet development are studied. The Kelvin-Helmholtz wave appears firstly when jet losts it's stability, and then the single vortex rolls up. After that, with the development of jet, the vortex structures begin to pair and merge because of the increasement of non-linear effects. It is also shown that the pressure distribution is directly relative to the large vortical structures.