喷管/飞行器后体一体化数值模拟

Numerical Simulation of Integration of Nozzle/Vehicle-Afterbody

采用 NND格式 ,进行了喷管 /飞行器后体一体化数值模拟。分析了喷管膨胀比和外流马赫数对后体阻力的影响 ,通过和实验数据对比 ,表明本文发展的计算方法是可靠的 。

When Mach number exceeds 2.0, engineering methods and ground test can not describe accurately the flow field near nozzle/vehicle afterbody. For aerospace shuttle, whose maximum Mach number is about 6.5, the situation becomes worse. The flow field near nozzle/vehicle afterbody is the mixture of nozzle internal flow and afterbody external flow and hence is very complicated. We aim to explore the solution of this difficult problem. In section 3, we explain the use of NND scheme to simulate integration of nozzle/afterbody. We selected Baldwin Lomax model for wall shear layer and Prandtl model for wake region. In section 5, we explain how to write down the five kinds of boundary conditions. In the numerical example of section 6, we give in Fig.7 the total calculated effect on afterbody drag of both nozzle expansion ratio and Mach number of external flow and give in Fig.6 the calculated pressure distribution on internal surface of nozzle for three values of NPR(nozzle pressure ratio): 2.0, 8.0, 15.0. Only for NPR=8.0 are test data available, and for NPR=8.0, our calculated cuvre agrees well with experimental data.