Extrapolation of a generic scramjet model to flight scale by experiments, flight data and CFD

Abstract

Based on ground and flight testing, a generic full scale scramjet combustion chamber was investigated to extrapolate the results obtained at small scale experiments. Numerical CFD validation was done for the experimental data for a duct size of 9.8mm height and wall porthole injection. Taking previous results of mixing and combustion performance enhancement into account, the configuration was extrapolated to a real full scale vehicle with a duct size of 300mm height. The combustion process in the full scale combustion chamber showed comparable flow topology changes and pressure rise due to variation in equivalence ratio. The different working modes of the scramjet such as the pure supersonic mode at lower equivalence ratio, a mixed subsonic/supersonic mode with a locked reverse flow area behind the injector at moderate equivalence ratio and choked flow at high equivalence ratio could be reproduced for both small and large scale ducts.