Techniques to Suppress Cavitation in Liquid Rocket Engines

ABSTRACT: Next generation liquid rocket systems, envision novel designs for cryogenic turbopumps that exhibit high suction performance with low inlet pressures, operate at high tip speeds to reduce size and weight, and can be throttled over a wide range of low, off-design flow conditions where the inlet flow quality is poor with large backflow. These are extremely demanding flow regimes which make the inducer susceptible to a range of cavitation instabilities that can lead to performance loss and potentially catastrophic damage due to large dynamic pressure loads. To mitigate these instabilities design strategies that employ cavitation suppression devices have to be explored to achieve robust performance over a wide operating range. The innovation proposed here is the development of a novel cavitation suppression concept that will be tested and the test data used to validate and mature the simulation framework, CRUNCH CFD as a design support tool. The resulting products at the end of the Phase II effort will be both a practical cavitation suppression device that is demonstrated to function for the flow regimes of interest, and a well-validated analysis tool, CRUNCH CFD, that can be used to predict performance and optimize designs of these devices. BENEFIT: This framework can be used as a design support tool for upper stage engines in the Next Generation Engine (NGE) program and would help reduce design cycle times. It would also support technology development efforts for NASAs SLS program where new boosters that have a heavy lift capability will be designed. It is anticipated that this product will be of interest as a design support tool to the aerospace industry. In addition, a broader market exists, comprising industrial pump designers who would be interested in using this product for designing high-energy systems such as boiler feed pumps and fuel injection pumps. In these applications, the pumps are required to perform at off-design conditions over extended time periods. They typically are required to be certified for a specified durable life operation (e.g. 40,000 hours) and have stringent vibration level requirements, making it critical that cavitation effects be eliminated or mitigated.