可压缩平面流中尖角处不定常涡产生的初始阶段的数值模拟

本文采用有限体积法结合高分辨率的ＴＶＤ（总变差不增）格式，对平面激波遇矩形、三角形障碍物问题进行数值模拟，采用Ｓｃｈｗａｒｚ变换生成计算网格，可使网格线在尖角处较密集且网格设置符合流场物理特性。初始阶段的流场复杂且粘性影响的尺度很小，模型中可以忽略流体的粘性。计算结果描述了平面无粘可压流中，由于弓形激波后熵与温度的不均匀性引起的尖角下游不定常集中涡的产生过程。数值计算与应我们要求所做激波管实验的光测结果相符合。

^ Numerical Modeling of the lnitial Stage of the Generation of Unsteady Vortices from Sharp Corner in Plane Compressible Flow

The impingement of a plane shock wave in air on a rectangular or triangular obstacle is simulated numerically with high resolution TVD(total variation di-minishing)scheme in finite volume forniulation with Schwarz transformation in mesh generation. The mesh lines are quite adaptive to the physical features of the unsteady flow field and concentrate locally near the corners.At the initial stage the flow field is complex,and the scale of viscous diffusion is very small and the viscosity of fluid in computation may be neglected.The unsteady genera-tion of concentrated vortices downstream of the sharp corner as the result of the nonuniformity of both temperature and entropy fields in plane inviscid compressi-ble fluid, induced by bow shock wave,is shown clearly and in accordance with optical measurements,performed by our request.