TECHNICAL ABSTRACT (LIMIT 200 WORDS) An innovative model for simulating cavitation in liquid rocket turbopumps using cryogenic working fluids is proposed. The formulation is based on a compressible gas-liquid framework that accurately models the acoustics in a multi-phase mixture. This methodology was successfully applied, in our Phase I effort, to simulate cavitating inducer performance in water. Our Phase II effort will extend this formulation to cavitation in cryogenic fluids which exhibit, relative to water, far more complex physics; cryogenic pumps operate at temperatures closer to the critical temperature of the working fluid making thermodynamic effects important. The model will account for the variation in the properties of the fluid as a function of the local fluid temperature that may vary due to energy requirements of vaporization/condensation. It will be incorporated within the commercially marketed code CRUNCH CFD that has a multi-element unstructured framework and is ideally suited for complex turbomachine configurations. This framework will be used as a design support tool to analyze inducer designs and in particular determine the suction specific speed at which head breakdown occurs. The limited reliability of current design tools in cavitating flow regimes makes this innovation a useful tool for turbomachine designers.
POTENTIAL COMMERCIAL APPLICATIONS The software product resulting from our Phase II effort directly addresses core needs of liquid rocket system engineers both in the commercial aerospace industry, as well as NASA. As part of the NASA Space Launch Initiative, there is a current need to design turbomachinery systems that can be throttled over a wide range of off-design conditions. Extensive cavitation under these conditions can detrimentally affect the performance and durability of these systems. Current design procedures largely rely on a combination of one-dimensional analyses and correlations derived from historical design practices. However, these tools have limited reliability in the cavitating flow regime and designers have to be very conservative in defining a safe operational range. Furthermore, commercial CFD tools currently available are not adequate to model the compressibility effects that arise in cryogenic pumping systems. The proposed modeling software CRUNCH CFD addresses these deficiencies and can play a valuable role as a design support tool for refining preliminary designs as well as rectifying problems with existing operational systems. In addition to the liquid rocket industry, this simulation software can also be used in a wide range of the broader commercial market including: 1) Industrial pump market (e.g. boiler feed pumps, nuclear reactor safety pumps, etc). 2) Marine propellers, and 3) Recreational high-speed water crafts such as jet-skis.
NAME AND ADDRESS OF PRINCIPAL INVESTIGATOR (Name, Organization Name, Mail Address, City/State/Zip) Ashvin Hosangadi Combustion Research and Flow Technology, 174 North Main Street, POB 1150 Dublin , PA 18917 - 2108
NAME AND ADDRESS OF OFFEROR (Firm Name, Mail Address, City/State/Zip) Combustion Research and Flow Technology, 174 North Main Street, POB 1150 Dublin , PA 18917 - 2108