Design of an Optimum Thrust Nozzle for a Typical Hypersonic Trajectory Through Computational Analysis.

摘要

An analysis of a planar supersonic nozzle for a NASP type vehicle was performed with a computer program that used the new upwind flux difference splitting (FDS) method. Thrust optimization, off-design performance, and cowl angle parametric analyses were accomplished, using FDS code, an oblique shock wave solver program, and a Scramjet cycle analysis code, at six points on a 1000 PSF maximum dynamic pressure trajectory, for the Mach numbers 7.5, 10.0, 12.5, 15.0, 17.5, and 20.0. Results from the single parameter number range from 7.5 to 20.0, the attachment angles identified as optimum for the respective trajectory points were 38.0, 38.6, 30.0, 24.6, 20.6, and 17.8. From this range of angles, the 20.6 degree nozzle was found to produce the minimum off-design performance losses over the entire trajectory. this deteriorization was based on selection criteria biased toward the higher Mach numbers. Using the 20.6 degree nozzle attachment angle, a cowl angle parametric analysis was performed to determine the extent to which off design performance losses could be recovered.