Investigations of time dependent flow phenomena in a turbine and a pump-turbine of Francis type
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Frequent shifts of output and operating mode require a pump turbine with excellent stability. Current researches show that large partial flow conditions in pump mode experience positive-slope phenomena with a large head drop. The pressure fluctuation at th ...
Editorial Office Chinese Journal Mechanical Engineering2012
Hydraulic pump-turbines are subject to a high periodic excitation due to the Rotor-Stator Interaction, RSI. Basically, the RSI is caused by the impeller blade passage in the wake of the guide vanes in generating mode, or upstream from the guide vanes in pu ...
Hysteresis phenomena demonstrate the lag between the generation and the removal of some physical phenomena. This paper studies the hysteresis phenomena of the head-drop in a scaled model pump turbine using experiment test and CFD methods. These lag is indu ...
The presented work consists of the presentation and discussion of unsteady experimental results of controlled vibration measurements for two single-blade and two cluster test cases subjected to the same subsonic flow conditions. The experiments were perfor ...
Modern pump-turbines are subject to frequent switching between the pumping and generating modes with extended operation under off-design conditions. Depending on the specific speed of the pump-turbine, the discharge-speed as well as torque-speed generating ...
Fatigue related problems in Francis turbines, especially high head Francis turbines, have been published several times in the last years. During operation the runner is exposed to various steady and unsteady hydraulic loads. Therefore the analysis of force ...
International Association For Hydraulic Research2012
Pump and turbine operations lead to head losses in the tailrace channel. Pumping discharge may be limited due to potential air entrainment into the pump shaft when the downstream reservoir is at its lowest level and the head losses are high. Regarding turb ...
The diversification of power generation methods within existing power networks has increased the requirement for operational flexibility of plants employing steam turbines. This has led to the situation where steam turbines may operate at very low volume f ...
The diversification of power generation methods within existing power networks has increased the requirement for operational flexibility of plants employing steam turbines. This has led to the situation where steam turbines may operate at very low volume f ...
The so-called rotating-stall (RS) is an undesired hydrodynamic phenomenon affecting the regular function of Francis-type pump-turbines. Stronger noise and vibration increase the risk of catastrophic failures and economic loses. In the past, such phenomenon ...