Numerical Validation of a Free-Flying Scramjet Powered Vehicle at Realistic Wind Tunnel Conditions

Abstract

One of the major objectives of the EC-co funded research project LAPCAT II is demonstrating positive aero-propulsive balance of a scramjet propelled vehicle in a wind tunnel and comparing this data to numerical simulations for validation of the CFD tools. For this, the LAPCAT MR2 hypersonic cruiser was scaled to wind tunnel dimensions. An optimization of the internal flow path was necessary, to cope with the different flight conditions and constraints in the wind tunnel environment. Therefore, a study featuring reactive CFD simulations was carried out. It was found that the best way to achieve a high combustion efficiency is to use a staged injection scheme in the combustor. Furthermore, from the experimental campaign carried out in the high-enthalpy facility at DLR (High Enthalpy Shock Tunnel Göttingen, HEG) validation data is available to compare the numerical studies against. It was found that still some uncertainties in the prediction of the aero-propulsive balance exists, but the thrust level could be sufficiently predicted by the CFD simulations within the measurement accuracy.