Reduced Order Modeling of Turbopump Inducers for Launch Vehicle Dynamical Systems
Advisor: Professor Spakovszky
Liquid rocket engine turbopump inducers can cavitate which may promote Pogo instability that can lead to catastrophic failure of the launch vehicle. Engine-coupled Pogo caused by dynamic instability arising from interaction of vehicle structural dynamics with thrust oscillations of liquid fueled propulsion system. Those thrust oscillations are a result of the pressure fluctuations that originate in the piping system, the engine’s injector, the combustion chamber, and/or the turbopump inducers when cavitating. Turbopumps operate at high rotational speed which leads to formation of vapor cavities that trigger Pogo. Subsequently, there is a direct link between inducer’s cavitation and the overall pogo oscillations. Two of the main challenges associated with this study are 1- disparity in findings about mechanisms for cavitation onset, and 2- parse amount of data on inducer dynamic behavior. This research introduces a new opportunity for dynamical system modeling capturing the structural dynamics effects, and thus demonstrates benefits of coupled dynamical system model for characterization of Pogo instability with direct link to inducer and pump design.