剪切应力输运k-ω湍流模型在细长弹体可压缩分离流中的改进

摘要

To investigate compressible turbulent separated flowfields over aircraft and missile surfaces, a modi-fied shear stress transport (SST) k-ωturbulence model was proposed.Turbulent separated flows were simulated by employing original and the improved SST k-ωmodel over an axisymmetric slender body at angle-of-attack 14°, Mach number of 2.5 and 0.7 respectively.Comparisons of distribution of limiting streamlines, the location and strength of separated vortex and pressure distribution on the wall with experimental results show that the ratio of Reynolds shearing stress and turbulent kinetic energy should be changed from 0.31 to 10/29 for simulating com-pressible turbulent separated flowfields over slender body.Calculation results of the location and strength of separa-ted vortex and pressure distribution on the wall using the modified SST k-ωmodel are closer to the experiments than the original SST k-ωmodel.%为研究飞机和导弹的细长体可压缩湍流分离流问题,对剪切应力输运(SST) k-ω湍流模型进行了改进.数值模拟了马赫数2.5和0.7、攻角14°下细长旋成体的湍流分离流场,给出了原SST k-ω模型和改进的SST k-ω湍流模型的细长体背风面极限流线、分离涡的强度和位置、物面压力分布的计算结果,并与实验结果进行了对比.结果表明,对计算细长体可压缩分离流动的绕流特性,SST k-ω模型引入的Bradshaw数(雷诺切应力与湍动能之比)应由0.31修正为10/29,修正后的SST k-ω模型与原SST k-ω模型相比,所计算的分离涡的强度和位置、物面压强分布与实验结果更接近.