大钝头短体跨音速大迎角不同流型的计算比较

COMPARISON OF COMPUTATIONAL RESULTS OF THE FLOW AROUND A BLUNT NOSED AND SHORT BODY AT LARGE ANGLES OF ATTACK

采用不同流型 (无粘 ,层流 ,湍流 )的数值模拟方法计算了绕大钝头短体外形的跨音速大迎角时的流态 ,并进行了比较分析。数值方法中选用 van Leer分裂格式离散无粘通量项 ,并构造了一种 Limiter函数以保证 TVD性质 ;采用中心差分格式来离散粘性通量项。湍流计算中采用了 B-L湍流模型。算例表明不同流型的流态共同特点是三维分离的非定常性 。

The separated flow structures of the transonic flow around a blunt nosed and short body at large angles of attack are calculated by using three different types (inviscid, laminar and turbulent) of numerical simulations. Numerical results are compared with each other. In the numerical calculation van Leers Schemes is used to discretize the inviscid flux term and a kind of limiter function is constructed to realize the TVD character. The viscous flux terms are discretized by using a central difference scheme. The B-L model is used in the turbulent flow calculation. Numerical results show that the common feature of the 3 different separated flow structures is the unsteady quasi-periodic character, while their detailed structures are quite different.