Development of Kerosene and Liquid Oxygen Gas Generator

Gas Generator are a subcomponent of turbopumps, which are needed to power large rocket engines. Low thrust (under 5,000 lbf) rocket engines typically use what is known as a blowdown type feed system to pressurize propellants and inject them into the chamber. A blowdown system uses high pressure gases like nitrogen or helium to pressurize the entire propellant tank. This simple approach is great for low thrust engines and small tank sizes. As engine thrust, and tank sizes grow, the system becomes heavier and begins to encounter multiple technical issues. For larger engines, turbopumps offer significant mass savings, at the expense of drastically increased complexity. Turbopumps are use pumps, driven by a turbine, to pressurize the propellants used in engines. Gas Generators generate a high energy flow of gas to power the turbine, usually by combusting the same propellants as the rocket engine they power. Rocket engines and gas generators have many similarities; however, gas generators have their own set of unique technical problems, on top of the typical problems contributed to rocket engines. The position of the gas generator upstream of a turbine, necessitates better mixing of propellants and the combustion products used than in a rocket engines chamber. Additionally, the temperature of the gases must be much lower than that of a typical engine, leading to extreme oxidizer / fuel ratios. Janus R, a 3,000lbf kerosene and liquid oxygen rocket engine designed by ERAU students was used to set requirements for the preliminary design of a small turbopump, from which the requirements for the design of a kerosene and liquid oxygen gas generator were derived. The preliminary and critical design of the gas generator are taking place this spring, followed by manufacturing, in preparation for a test campaign in the fall semester.