Fuel-rich combustion characteristics of hybrid rocket engine

Abstract

Fuel rich combustion in hybrid rocket engine offers numberous advantages over classical one. Together with staged combustion system which forms the staged hybrid rocket engine offers low time variation of oxidizer to fuel ratio and high combustion efficiency without sacrificing the unique characteristics of hybrid rocket engine, such as stop-restartability and oxidizer mass flux dependent fuel regression rate. To generate fuel-rich gas, control of equivalence ratio is essential. Therefore fuel type, fuel grain geometry, O2 and N2 mixture oxidizer and AP were introduced throughout the research. The sensitivity of each parameter to equivalence ratio was evaluated as well as the behavior with respect to combustion gas temeprature and O/F variation through the series of combustion tests. As a result, averaged combustion gas temeprature as low as 1290K and O/F variation of 1.04 fuel-rich gas was successfully produced with pure HTPB and 42% O2 content mixture oxidizer condition. Effect of AP addition in fuel-rich combustion was evaluated, and concluded to be favorable for the fuel-rich gas generator system. © 2015, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.