Numerical analysis of flow in pumpturbine operating in Sshape region
(1. College of Energy and Power Engineering,Lanzhou University of Technology,Lanzhou,Gansu 730050,China; 2. Turbine Laboratory,State Key Laboratory of Hydropower Equipment, Harbin,Heilongjiang 150040, China)
Abstract：In order to study the characteristics of internal flow in a pumpturbine operating in the Sshape region, the flow in the model pumpturbine in a pumped storage power station in China was simulated by using CFD codeCFX. The detached eddy simulation model (DES) that is more precise than the traditional RANS model was applied in the simulation, consequently, the internal flow pattern and performance parameters of the pumpturbine were obtained; and compared with the experimental data and the theoretical analysis results, respectively. It was shown that the results of DES model are quite good, causing the error between the estimated and experimental performance is less than 3%; further, the internal flow in the runner are in good agreement with theoretical analysis as well. As the flow rate decreases, the flow separation phenomenon near the runner inlet was strengthened gradually, and eventually a vortex was developed in the flow passages, causing a blockage to flow. Note that the vortex can induce rotorstator interactions among the runner and double circular cascade, which will results in instability of flow in the whole passage.
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