Euler and Navier-Stokes Simulations of Two-Stage Hypersonic Vehicle Longitudinal Motions

The separation maneuver of an idealized two-stage hypersonic vehicle is aerodynamically investigated at a freestream Mach number of 6.8. The focus is on the calculation of unsteady  owŽ elds arising from a pitching and a translatorymotion as part of the complete separationmaneuver. The numerical simulations are based on a Ž nite volumemethod for solutions of the two-dimensional unsteady Euler and Navier–Stokes equations. The method is employed to compute the hypersonic  ow over a blunt orbital stage including the recirculation zone in the rear of the orbital vehicle. The carrier stage is modeled as a  at plate parallel to the undisturbed  ow. The orbital stage, interfering with the carrier, performs a deŽ nedmotion at zero incidence. The results include theMach number and pressure distributions, as well as the aerodynamic coefŽ cients. The separation process is dominated by re ecting shock waves occurring during the maneuver between the carrier stage and the orbital stage. The position and intensity of the shock waves are a function of speed, distance, and incidence between the two stages. The main intention is to analyze the motion-inducedunsteady aerodynamic effects and the associated  ow physics predicted by Euler and Navier–Stokes solutions.