Experimental Demonstration of the Vacuum Specific Impulse of a Hybrid Rocket Engine

Abstract

As part of the cooperation between Onera and Nammo Raufoss on hybrid propulsion, a small hybrid rocket engine was tested in the Onera vacuum test facility to demonstrate the experimentally achievable vacuum specific impulse. The Onera hybrid rocket engine, fitted with regression rate sensors, was modified to accommodate the catalyst bed and a vortex injector, both provided by Nammo Raufoss. The demonstrated combustion efficiency was above 98% and the specific impulse was experimentally proven to be above 270 s for a conical nozzle with an expansion ratio of 50.