不同湍流模型在三维后台阶数值模拟中的对比

摘要

数值模拟是飞行器设计的重要工具, 如何精确模拟分离流动, 其关键在于选择合适的湍流模型.针对分离流动中典型的后台阶流动, 采用不同的湍流模型进行三维数值模拟分析, 其中包括Spalart-Allmaras (简称SA) 湍流模型、两方程k-Omega SST (简称SST) 湍流模型和显式代数雷诺应力模型 (EARSM) , 并与实验结果进行比较.研究结果表明:EARSM对于后台阶分离涡回流区的模拟结果最好, 优于SA与SST湍流模型, SA模型对于剪切层模拟稍好一点.综合来说, EARSM模型对于回流区分离涡的模拟较好, 在剪切层位置其模拟结果也和实验较为接近, 能较好地反映后台阶的分离流动.%Numerical simulation has always been an important tool for aircraft design. How to accurately simulate separated flow is the bottleneck of choosing appropriate turbulence model. Aiming at the typical back-step flow in separated flow, three-dimensional numerical simulation analysis was carried out using different turbulence models, including Spalart-Allmaras (SA) turbulence model, two-equation k-Omega SST (SST) turbulence model, and explicit algebraic Reynolds stress model (EARSM) . The results were compared with the experimental results. The findings indicate that EARSM is superior to SA and SST turbulence models in simulating the back-step separated eddy backflow region, and SA model is a little better in simulating the shear layer. Generally speaking, EARSM model can better simulate the separation vortices in the recirculation zone, and the simulation results at the shear layer position are close to the experimental results, which can better reflect the separation flow in the back-step.