隐式紧耦合SST和TNT湍流模型的高速流动数值模拟

将SST(shear stress transport)和TNT(turbulent/non-turbulent)湍流模型输运方程与平均流场控制方程进行隐式紧耦合求解,结合当地时间步长方法和湍流源项隐式处理确保求解过程的快速和稳定.采用AUSMPW+(AUSM by pressure-based weight functions)格式和LU-SGS(lower-upper symmetric GaussSeidel)隐式紧耦合方法对高超声速压缩拐角流动、锥柱裙流动和超声速非对称激波/边界层干扰问题进行了数值模拟.计算结果与实验值的对比表明:SST模型和TNT湍流模型可以很好地预测15°压缩拐角流动的壁面压力和热流密度;随着压缩拐角的增大,计算结果与实验值偏差增大;可压缩性修正对压缩拐角流动的压力和热流密度分布有很大影响,对超声速非对称激波/边界层干扰流动影响很小;隐式紧耦合方法比显式紧耦合方法具有更好的收敛特性.

Numerical simulation of implicit fully coupled SST and TNT turbulence models for high speed flows

SST(shear stress transport) and TNT (turbulent/non-turbulent) turbulence models were solved by implicit fully coupled with the transport and mean flow control equations. Techniques of local time step and implicit treatment of turbulence source term were used to accelerate and stabilize the calculation. Test cases of hypersonic compression corner flow, conical cylinder flare flow and supersonic asymmetric shock wave/boundary layer interaction were simulated by the AUSMPW⁺ (AUSM by pressure-based weight functions) scheme and LU-SGS (lower-upper symmetric Gauss-Seidel) implicit fully coupled method. The results show that:SST and TNT turbulence models used can predict the wall pressure and heat flux of the wall at the 15 degree compression corner flows well. Discrepancies between calculated and experimental results increase with the increase of compression corner. Compressibility correction has a great effect on the pressure and heat flux of compression corner flows and has little effect on supersonic asymmetric shock wave/boundary layer interaction. The implicit fully coupled method shows better convergence characteristic than explicit coupled method.