Nozzle/Cowl Optimization for a Hypersonic Vehicle on a Typical Trajectory

摘要

An investigation of the effects of simultaneous variation of the nozzleattachment and cowl deflection angle on the performance of a two-dimensional nozzle used on a hypersonic vehicle such as the National Aero-Space Plane (NASP) was performed using a two parameter optimization procedure. Total thrust optimization was accomplished using a Flux-Difference-Split (FDS) cods, a RAMJET Performance Analysis program, and an oblique shock wave solver program, at sixteen points on a 1000 psf dynamic pressure trajectory for Mach numbers from 10.0 to 25.0. A single parameter optimization of the total thrust using a variable nozzle attachment angle was accomplished first to establish a reference frame. Effects of a deflected cowl on the nozzle flow field were explored. The optimum nozzle attachment and cowl deflection angle maximized the total thrust by increasing nozzle wall pressure without an excessive increase in pressure drag. The total thrust found by the two parameter optimization was increased at every point on the trajectory over the total thrust obtained from the single parameter optimization. This study shows that the cowl deflection angle starts negative, increasing from -0.493 degrees at Mach 10 to 3.01 degrees at Mach 25.... Hypersonic Nozzle, Optimum Thrust Nozzle, Scramjet Nozzle optimization, Hypersonic Vehicle.