压力恢复系统扩压器激波串现象的数值模拟

通过求解由S-A一方程湍流模式封闭的三维雷诺平均Navier-Stokes方程,采用有限体积方法对激光器压力恢复系统变截面扩压器常温状态下的三维流场进行了数值模拟.数值计算和实验符合良好,较好模拟了扩压器中由激波/边界层干扰诱导的复杂流场的流场特性并再现了流场中的"激波串"和"伪激波"现象.本文对激波串的形成机理进行了分析,发现了几种变截面扩压器特有的激波串结构,并研究了扩压器扩张角对扩压效率的影响.

Numerical simulation to the pseudo-shock of the supersonic diffuser in the pressure recovery system

Complicated flow fields in the supersonic diffusers with expanding cross section areas under normal temperature condition are simulated by solving the Reynolds-averaged Navier-stokes equations.Using the finite volume scheme with some advanced features in the numerical algorithms,together with the Spalart-Allmaras turbulence model,the predicted pressure distributions are in good agreement with the experimental results.According to the numerical results,the mechanism and flow structures of the shock train are identified and analyzed,and the influences of semi-expansion angle on the efficiency of pressure recovery are discussed.