HYPERSONIC AERODYNAMIC CHARACTERISTICS OF A PROPOSED SINGLE-STAGE-TO-ORBIT VEHICLE

The hypersonic aerodynamic characteristics of a candidate winged-body single-stage-to-orbit vehicle that features wing/tip-fin controllers a nd elevon/body/flap control surfaces are predicted at points along a n ominal trajectory for Mach numbers from 5 to 27 and angles of attack f rom 19 to 32 deg. Predictions are derived from surface properties base d on flow solvers for inviscid and viscous, laminar flows for a perfec t gas or reacting (equilibrium or nonequilibrium) gas. At a Mach numbe r of 22, the lateral aerodynamic characteristics of the vehicle are de termined for an inviscid analysis at sideslip angles of 2 and 4 deg an d 32-deg angle of attack; a viscous analysis demonstrated the effect o f gas chemistry modeling on surface pressure and was used to determine the incremental aerodynamics for control-surface deflections. The res ults show that the longitudinal pitch characteristics of the baseline configuration, i.e., zero-control surface deflections, are significant ly altered by real-gas chemistry at angles of attack greater than 30 d eg and Mach numbers greater than 9, and that aerodynamics derived from inviscid solutions are of sufficient accuracy for preliminary analysi s. Also, it is shown that a Mach number of 22, the choice of gas chemi stry model has a large impact on surface pressure levels in highly loc alized regions on the vehicle and that the vehicle ran be trimmed at c ontrol-surface deflections less than 11 deg.