FP-DSMC 하이브리드 방법을 활용한 재사용 발사체의 유동 해석

Abstract

In the space industry, reusable launch vehicles have gained significant attention as a way to reduce launch costs. SpaceX succeeded in recovering the first stage of Falcon 9 and entered it into commercial use. The Falcon 9 first stage undergoes a series of maneuvers, including boost-back burn and entry burn, after the main engine cut off (MECO) and separation from the second stage. Analysis of the thermal loads on the rocket is a crucial factor in thermal protection system (TPS) design. During the boost-back burn at high altitude, a highly under-expanded plume is formed. Due to the rocket's ascent speed, shockwave is generated within the hypersonic flow. During the re-entry burn, the interaction between shockwave and jet plume leads to the formation of a shockwave. Re-circulation region formed during the plume-shock interaction causes the plume to return near the rocket. The plume returning near the rocket could concentrate thermal loads on the rocket's surface. In this study, preliminary study for analyzing the flow on the reusable launch vehicle undergoing re-ignition at the high-altitude. For the analysis, both the freestream and the propellant had been assumed to be Argon. The Direct Simulation Monte Carlo (DSMC) method has been utilized to simulate nonequilibrium flow, and the hybrid FP-DSMC method has been employed to improve efficiency.