粘性跨音速喷管流场计算

COMPUTATION OF TRANSONIC VISCOUS FLOW IN NOZZLE

关键词:  喷管  跨音速流  粘性流  流场  计算

Key words:  Nozzle  Transoinc flow  Viscous flow  Flow field  Computation

摘要:

本文继用隐式近似因子分解法成功地计算无粘跨音速喷管流场之后,用同样的方法,结合任意曲线坐标系,通过非定常方程在相当长时间后的定常解,针对矩形截面喷管和轴对称喷管粘性跨音速流场,求解了可压缩层流薄层N-S方程,获得了核心流,特别是边界层中的流动参数.对于矩形截面和轴对称两种喷管进行了计算,其结果和实验数据相当一致.将本文的方法应用到粘性两相流动计算,可望较多的节省机时.

Abstract:

In thispaper,having successfully computed inviscid transonic flow in nozzle using same method,we solve compressible laminar thin-layer N-S equations in conservation form adopting an implicit approximation-factorization algorithm in conjunction with generalized body-fitted coordinates.The parameters in core-flow, especially in boundary layer,are obtained through asymptotic solution of unsteady equations after suitable long time.The computed examples are the transonic viscous flow filed in two kinds of nozzle, one possesses rectangular section and the other axisymmetric.The agreement of computation results in comparison with measurements is very good for two kinds of nozzle. Many researchers adopted explicit algorithm,but we adopted implicit one.In our paper,CFL number may be taken to 150.Convergent speed is very quick and consequently the computer time using implicit algorithm in comparison with using explicit one is saved greatly. The comsumption of computer time may reduce to acceptable degree if the method presented in this paper is used to calculate viscous twe-phase rocket flow in nozzle.