Experimental and numerical investigation of an embedded rocket ramjet combustor

This study proposes an embedded rocket ramjet, a novel combined ramjet engine, that can operate at high altitude and low pressure. The embedded rocket ramjet combustor is investigated experimentally and numerically to predict its characteristics. Experiments are performed in a direct-connect ground test facility to measures the wall pressure and total pressure at the combustor exit. Three-dimensional Navier-Stokes equations and species transport equations are solved numerically. A compressible reactive shear stress transport k-omega) turbulence model with reduced chemical kinetics of a surrogate model for kerosene is used to study the flow characteristics and overall performance of the combustor. Test results show that the embedded rocket can significantly increase the combustor pressure. Numerical analysis shows that the embedded rocket increases the mixing efficiency, combustion efficiency, and thrust but decreases the specific impulse.