Numerical Simulation of Supersonic/Hypersonic Flow for TSTO’s Staging Separation

For the next-generation space transportation system, two-stage-to-orbit (TSTO) is one of the possible concepts. This paper discusses the aerodynamic effects around the TSTO which consisted of orbiter and booster at the hypersonic ascend and the separation using the computational fluid dynamics. The effects of shock wave interaction to aerodynamic coefficients were investigated with changing freestream velocity, angle of attack, and relative position between the orbiter and booster. Firstly, the aerodynamics at the separation of the ascending booster and orbiter was investigated. It was found that the orbiter and the booster behave oppositely on the lift and the moment_. It means both vehicles can come to separate each other without any control. The shock wave interactions and reflections between booster and orbiter moment showed oppositely. At the separation, although the moment of the booster had negative value and decreases when α decrease from α = 0, orbiter kept positive value. In this study, the model changed relative positions were also investigated. Orbiter’s horizontal position Δx-changed model indicated higher moment than that of standard one. Separation angle θ-changed model had negative moment value. To investigate the effects due to the combination of the orbiter and the booster, two configurations (the combined and uncombined (booster)) are compared. As horizontal direction force; the drag was not related to shock wave interaction. On the contrary, the lift (perpendicular direction force in the freestream direction) was related to shock wave interaction. Accordingly, in all phase moment, it was showed that the orbiter and the booster can separate successfully due to the shock interactions.