跨声速和超声速流中激波/边界层干扰数值模拟

对SST湍流模型中的Bradshaw常数a1进行了修正,并对跨声速和超声速流中激波/边界层干扰进行了数值模拟研究,空间离散采用二阶精度差值的低耗散通量分裂格式(LDFSS),时间离散采用对称高斯-赛德尔(SGS)算法。结果表明:在跨声速流动中,计算得到的壁面压力分布、分离区长度和速度剖面都与实验值吻合较好,而且很好地模拟了典型的λ激波结构;在超声速流动中,修正后模型的计算精度较原始模型有了较大改善,计算得到壁面压力分布和分离点的位置都和实验值吻合较好。

Numerical simulation of shock wave/turbulent boundary-layer interactions in transonic and supersonic flows

The Bradshaw’s constant a1 in SST turbulence model was modified and the modified model was applied to simulate transonic and supersonic flows including shock wave/turbulent boundary-layer interactions.The solver used second-order accurate upwind differencing to discretize the convective terms and Edwards’s low-diffusion flux-splitting(LDFSS) scheme to evaluate the flux.The linear system of equations was solved using a point-iterative symmetric gauss-seidel(SGS) scheme.The computational results of the wall pressure distributions,separation length,mean velocity profiles agree well with the experiment in transonic flows.Moreover,the lambda shock is discerned clearly and showed good agreement with experiment.In the case of supersonic flows,the modified model yields more reasonable prediction of the wall pressure distribution and the separation point location,compared with the original SST turbulent model.