Analysis of the dynamic response of pump-turbine runners- Part I: Experiment

When in operation, pump-turbine runners have to withstand large pressure pulsations generated by the rotor-stator interaction. The analysis of the dynamic behavior of these structures is necessary to avoid damage. For this analysis a realistic model of the runner is necessary. When the runner is submerged in water and inside the casing, its dynamic response is greatly affected. The added mass effects of the surrounding fluid and the proximity of the head-cover and bottom-cover may reduce the natural frequencies. The frequency reduction produced by the added mass effects and the influence of the boundary conditions has to be known for a safe design of the runner. In this paper an experimental investigation on the dynamic response of a model runner is presented. A reduced scale model of a pump-turbine was tested outside and inside the casing with different boundary conditions. For the excitation of the runner at different frequencies piezoelectric patches were used. The response was measured with miniature accelerometers located in several positions inside the runner. From the measurements the natural frequencies and mode-shapes of the runner were calculated using EMA. The influence of the added mass and of the boundary conditions is presented and discussed.


Published in:
Proceedings of the 26th Symposium on Hydraulic Machinery and Systems, 1, 1-8
Presented at:
26th Symposium on Hydraulic Machinery and Systems, Beijing, China, August 19–23, 2012
Year:
2012
Publisher:
International Association For Hydraulic Research
Laboratories:




 Record created 2018-05-20, last modified 2019-08-12

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