SBIR Phase II: Numerical Simulation of Cavitating Flows Using an Innovative Probability Density Function Model for Phase Change

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*** 9801239 Singhal This Small Business Innovation Research(SBIR)Phase II project will further develop, validate and demonstrate the Probability Density Function (PDF) cavitation model for multi-dimensional steady and transient simulations of cavitating flows. Phase I has shown the feasibility and benefits of including the effects of turbulent pressure fluctuations on phase change rate, by using a PDF approach. While this effect has, as postulated, improved both the accuracy and numerical stability of solutions, further study is needed to account for additional physical phenomena such as bubble dynamics and presence of non-condensable gases. The Phase II effort will focus on a) developing appropriate functions for phase change rates by making use of the Rayleigh-Plesset equation and partial pressure concepts, and b) improving robustness and efficiency of the iterative solution process. Each modification will be systematically assessed by comparing numerical solutions against selected benchmark data, covering wide range of problems and flow conditions. The final model will be applied to three classes of problems from aerospace, naval/marine, and automotive industry The developed cavitation model will enable improved designs of engineering equipment using pumps, propellers, orifices, hydrofoils, and hydrostatic bearings and biomedical devices such as mechanical heart valves. The cavitation model will be useable with cooercial programs. ***