EXPERIMENTAL INVESTIGATION OF THE RBCC ROCKET-EJECTOR MODE

The experimental results from the study of the rocket-ejector mode of a Rocket Based Combined Cycle (RBCC) engine are presented and discussed. The experiments involved systematic flowfield measurements in a two-dimensional variable geometry rocket-ejector system. The rocket-ejector system utilizes a single two-dimensional gaseous oxygen/gaseous hydrogen rocket as the ejector. To gain a thorough understanding of the rocket-ejector's internal fluid mechanic/combustion phenomena, experiments were conducted with both direct-connect and sea-level static configurations for a range of rocket operating conditions. Overall system performance was obtained through global measurements of wall static pressure profiles, heat flux profiles and engine thrust, whereas detailed mixing and combustion information was obtained through Raman spectroscopy measurements of major species (oxygen, hydrogen, nitrogen and water vapor). Rocket-ejector experimental results for both the Diffusion and Afterburning (DAB) and Simultaneous Mixing and Combustion (SMC) geometries are presented here. For the DAB configuration, experiments were conducted for both direct-connect and sea-level static configurations, whereas SMC