一种适用于超音速边界层的湍流转捩模式

建立一种合理反映扰动模态和可压缩性影响的新型k-ω-γ转捩模式.其主要特点为:(1)假设脉动动能k 由湍流脉动部分和非湍流脉动部分组成，且在模化后者时采用了稳定性分析的结果; (2)在间歇因子γ方程的源项中，构造了具有``自动判断转捩起始位置'功能的函数; (3)通过构造新型的物面法向长度尺度，保证了模式中所有的表达式均由当地变量构成，可以方便地应用于现代CFD程序之中. 该模式在亚音速、超音速和高超音速条件下的边界层流动中进行了验证. 计算结果表明，该模式可应用于较宽马赫数范围内的自然转捩以及旁路转捩过程，所具有的捕捉流动转捩的性能优于国际上的现有模式. 

A NEW TRANSITION/TURBULENCE MODEL FOR THE FLOW TRANSITION IN SUPERSONIC BOUNDARY LAYER

A new k-ω-γ transition/turbulence model is established to consider the instability modes associated with the compressibility. The particular features of the new model are: (1) the fluctuating kinetic energy k includes the non-turbulent, as well as turbulent components modelled with the stability analysis; (2) a function for the source term in γ equation is developed to trigger the transition onset; (3) it is strictly based on local variables by introducing a new length scale normal to wall and compatible with the modern CFD methods. The present model was numerically proved to be applied into the analyses of natural transition and bypass transition with a wide range of Mach number.