Experimental Study on Rocket-Ejector Systems

Experimental studies on the RBCC propulsion systems were initiated with the objective of understanding their operational characteristics and proposing an original design. Preliminary tests with simplified test systems have been conducted to obtain basic data on characteristics of air entrainment in the rocket-ejector mode under ground level static condition. A 400 N class small solid propellant motor has been utilized as a primary rocket subsystem because it is convenient for generating high pressure and high temperature combustion gas. Cylindrical ducts, which are variable in length, have been used as the mixers. A single circular cross-sectional centerline-mounted rocket has, therefore, been used for the rocket-ejector configurations. A quasi one-dimensional analysis was proposed to distinguish the internal flow fields and to justify the experimental findings. As the results of the tests and the analyses, characteristics of the internal flow, which was formed by interaction of a rocket-exhaust flow with the entrained-air flow, could be described.