用可实现k-ε模式对细长体大攻角分离流场的数值模拟

Numerical simulation of separated flows over slender body at high-angle-of-attack with k-ε model comforming realizability

利用一种符合可实现性条件的k-ε两方程模式,通过求解可压缩性Navier-Stokes方程,数值模拟了细长旋成体在M=2.5和0.7、中等大攻角下的湍流绕流流场。定性分析了背风面分离涡的发展过程和湍流粘性比等流动特征,对背风面主涡强度和涡核位置、物面压力分布、集中力和力矩与已有的试验结果进行了细致的定量对比,证实了数值模拟的有效性。

Adopting a k-ε two-equation turbulence model which followed the realizability rule, the turbulent flow fields around a slender axisymmetric body at moderate high-angle-of-attack （14 degrees）, M= 2. 5 and 0. 7 were numerically simulated by solving compressible Navier-Stokes equations. Qualitatively analyzed flow characteristics, including the leeward vortices developing process and turbulence viscosity ratio, et al. Detailed, quantitative comparisons were done for （1） strength of the primary vortex and location of the vortex core; （2） pressure distributions on the wall; （3） forces and moments. All these analyses and comparisons showed that the numerical simulation was effective, and the results were reliable.