Computational Fluid Dynamics Modeling and Verification of a Submersible Pump-Turbine Runner: Preprint

An innovative reversible pump-turbine runner with a 180-degree flow direction reversal has been designed and optimized using Computational Fluid Dynamics (CFD) modeling. The reversible pump-turbine configuration provides a cost-effective means of achieving adequate submergence below tailwater, thereby permitting higher-speed turbine and generator operation and reduced equipment size. Results from CFD modeling and analysis of the hydraulics and runner design are presented. The benchmarks for these parameters are the performance parameters of conventional pump-turbines with scroll-case turbine inlets. The model efficiencies were independently verified, and a sensitivity analysis of the results is presented. The results do not reveal a region of pump instability that is characteristic of pumps and pump-turbines with scroll cases. CFD modeling and analysis of the hydraulics and runner design are presented. The benchmarks for these parameters are the performance parameters of conventional pump-turbines with scroll-case turbine inlets. The model efficiencies were independently verified, and a sensitivity analysis of the results is presented. The results do not reveal a region of pump instability that is characteristic of pumps and pump-turbines with scroll cases.