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 flowfields arising from a pitching and a translatory motion as part of the complete separation maneuver. The numerical simulations are based on a finite volume method for solutions of the two-dimensional unsteady Euler and Navier-Stokes equations. The method is employed to compute the hypersonic flow over a blunt orbital stage including the recirculation zone in the rear of the orbital vehicle. The carrier stage is modeled as a flat plate parallel to the undisturbed flow. The orbital stage, interfering with the carrier, performs a defined motion at zero incidence. The results include the Mach number and pressure distributions, as well as the aerodynamic coefficients. The separation process is dominated by reflecting 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-induced unsteady aerodynamic effects and the associated flow physics predicted by Euler and Navier-Stokes solutions.