超声速湍流流场的RANS/LES混合计算方法研究

采用对接/拼接网格技术,建立了基于分区混合和基于湍流尺度混合的双重RANS/LES混合计算模型,并对环翼低速绕流、翼型跨声速绕流和球锥带凹窗外形二维超声速绕流进行了初步的数值模拟.环翼和翼型绕流计算表明,该混合模型可给出较合理的湍流宏观平均量;球锥带凹窗外形二维超声速绕流计算表明,该混合模型可得到超声速瞬态湍流脉动流场,凹窗处存在复杂的旋涡结构和波系结构,呈现较大尺度的脉动.但该模型还需要进一步的考核验证.

Research on the RANS/LES hybrid method for supersonic/hypersonic turbulence flow

In this paper, a new double hybrid RANS/LES method is development for supersonic and hypersonic turbulence flows in order to research aero-optical effects. First, the computational zone is divided to RANS zone and RANS/LES zone, this is a zonal hybrid method based on patched grid technology. Secondly, in RANS/LES zone, a new hybrid model based BL turbulence inner model and Smagorinsky LES model is development. It belongs to DES method by Spalart, and is similar to Smagorinsky-Lilly model. Then the new method is used to compute several examples such as airfoil transonic turbulence flow, the results show that it can get reasonable turbulence average parameters. At last, a 2D sphere-cone with optical window model is computed by the new method, the supersonic and hypersonic turbulence fluctuation flow-fields is getting. It shows that there are complex vortex structures and wave structures and their interactions over the window, induced density fluctuation with high amplitude. But the new double hybrid RANS/LES method should be validated carefully.