Investigation on Dynamic Stresses of Pump-Turbine Runner during Start Up in Turbine Mode

The startup process occurs frequently for pumped storage units. During this process, the rotating rate that changes rapidly and unsteady flow in runner cause complex dynamic response of runner, sometimes even resonance. sharp rise stress large-amplitude stresses will greatly shorten fatigue life. Thus, study start-up turbine mode is critical to safety operation. This paper introduced a method coupling one dimensional (1D) pipeline calculation three-dimensional computational dynamics (3D CFD) simulation analyze transient units obtain more accurate reliable results during start up process. According results, ring near fixed support increased quickly as rose became larger than at fillets leading edge band later stages start-up. In addition, it was found can be caused by rotor stator interaction (RSI), but also could generated severe pressure fluctuation clearance, which factor stresses. facilitate further estimation changing cases, well analysis