二元矢量喷管流场的N－S方程计算

对二元矢量喷管在不同工况下的流场进行了数值模拟。求解的控制方程为三维非定常Ｎ－Ｓ方程。空间方向用有限体积离散，时间方向用Ｒｕｎｇｅ－Ｋｕｔｔａ法推进。粘性项的计算上采用了一种有限体积框架下新的离散化方法。湍流模型采用了广泛使用的Ｂａｌｄｗｉｎ－Ｌｏｍａｘ代数模型。计算表明，本文方法能准确地计算二元矢量喷管、非矢量喷管在设计与大设计落压比下的流场。

NAVIER-STOKES PREDICTIONS OF 2-D VECTORED NOZZLE FLOWS

In this paper,the viscous flows in the two-dimensional vectored and unvectored nozzles are numerically simulated by three-dimensional time-dependent Navier-Stokes equations in conservation forms.Finite volume discretization is used in spatial form and Runge-Kutta method in time marching direction.A new viscous terms' discretization in the frame-work of the finite volume method is used which has the advantages of less operation counts and full conservation.A modified Baldwin-Lomax algebraic turbulent model and wall function law are also adopted in the prediction.Comparision of numerical predictions with experiments shows that the Navier-Stokes code can accurately predict the flow fields in the vectored and unvectored nozzle where the flow is predominantly two-dimensional at the designed nozzle pressure ratios or above.Discrepancies between predictions and experiment are found at lower nozzle pressure ratios where separation typically occurs in a large portion of the nozzle.