COMPUTATIONAL ANALYSIS OF A BLUNT BODY RE-ENTRY VEHICLE AND UNSTART CONDITIONS IN A HYPERSONIC WIND TUNNEL

Abstract

The study of hypersonics has become a focal point not only for the Department of Defense but also multiple civilian agencies. This study was meant to focus on the high- speed fluid dynamics related to this regime of flight using the facilities at the Naval Postgraduate School. The current Gas Dynamics Laboratory (GDL) high-speed wind tunnel was capable of generating long runtime high Mach number flows. With only slight modifications to the current facilities, it was determined by previous research that a wind tunnel capable of sustained Mach 5.0+ flows for greater than 20 minutes was attainable. With this new test facility in mind, a computational fluid dynamics analyses was conducted on the feasibility of testing a portion of a blunt body hypersonic vehicle intended for re-entry purposes. This project was able to provide significant data for NASA’s sample delivery project and determined the viability of tests at the GDL given the supplied vehicle geometries. An additional analysis was conducted using the tunnel’s test chamber geometry as a means of studying hypersonic inlet unstart conditions. The proposed Mach 5.0+ tunnel test section was identified as being analogous to the inlets of numerous hypersonic air breathing vehicles. By increasing the pressure at the outlet of the system, repeatable unstarts were achieved. This analysis provided an excellent basis for analytical testing moving forward and real-world experimentation on hypersonic unstarts.