Validation of Bucket Flow Simulation using Dynamic Pressure Measurements

The paper below is a follow up of the authors contribution to the IAHR 2002, in which the simulations of the flow through Pelton buckets were presented. In 2002, a good consistency between the predicted and measured efficiency was presented. This paper will first present a discussion of several possible strategies for bucket flow simulation. It will be described, why the authors favour the 3 bucket approach instead of a periodic simulation. The second part describes the detailed validation of the simulation with results of a dynamic pressure measurements campaign carried out in the rotating buckets. It will be shown, that the predicted time dependent pressure trends are in good agreement with the measurements. Both, the shape and the height of the development are well predicted. Even the situations where values below ambient pressure occur are in remarkable agreement.