Development of a nitrous oxide propane combustor

This work focuses on the development of a nitrous oxide (N₂O)/propane (C₃H₈) rocket engine. This propellant combination is potentially a high energy alternative to the present space propulsion systems that use hypergolic or cryogenic liquids, or solid propellants. The research was accomplished in two phases. Phase I work resulted in a successful demonstration of the key technologies associated with the development of such a propulsion system. Phase II testing employed a vortex injector with a smaller chamber volume in an effort to stabilize combustion and boost performance. Testing was conducted over a range of mixture ratios from 4 to 8, and characteristic lengths of 12&inches;, 36&inches;, 72&inches;, and 108&inches;. Phase I testing produced promising results with efficiencies near 85%. Instances of low frequency pressure oscillations were observed during Phase I testing. Phase II testing produced repeatable, steady firings over the entire range of mixture ratios with efficiencies near theoretical equilibrium calculations. Alternatives to propane as a fuel should be investigated in order to make this system more attractive for wide spread industrial use and larger applications.