超燃冲压发动机非对称喷管非设计状态性能计算

由非对称喷管的设计程序,以实际飞行马赫数6为设计条件,取不同的几何控制参数,获得一系列对应的喷管等熵型线。对其进行附面层修正后,在不同飞行工况下,用CFD软件分别对不同外型的喷管流场进行了计算,讨论了上下壁面进口处初始膨胀角之比F对非设计工况下喷管性能的影响。然后,对F=0的喷管型线截去约60%,用CFD软件计算了不同飞行工况下的流场,讨论了截短对非对称喷管非设计状态性能的影响。结果表明:F对非设计状态喷管性能影响显著;截短后喷管进出口冲量差减小,升力和俯仰力矩减小。

Numerical simulation of single expansion ramp nozzle for scramjet on the off-design point

Under the conditions of the Ma 6 free stream and the ratio of initial expansion angle F,different nozzle configurations are obtained.Then the isentropic contours are refined by the boundary layer displacement.Then,in order to find out the effects of parameter F on nozzle off-design performance,the flow fields of these nozzle configurations under different free stream Mach numbers are numerically studied.At last,the "cutting down" effects on the SERN off-design performance are numerically simulated.The numerical results reveal that the parameter F and "cutting down" influence the nozzle performance on the off design point noticeably.The impulse difference between nozzle entry and exit decreases if the 60% length of the F=0 nozzle is cut off,and lift and pitch moment reduce evidently.