Publication Date:
2014-12-11
Description:
Velocity measurements were performed in the draft tube cone of a 1:5.1 scaled model of the Tokke hydropower plant, Norway; also known as the Francis-99 model. Results from the laser Doppler anemometry measurements undertaken at three operating points will be used as validation data for an upcoming workshop on the state of the art of Francis turbine numerical simulation. With the turbine operating at the best efficiency point, a sensitivity analysis of the flow parameters head, flow rate and runner rotational speed shows that the effects on the dimensionless velocity profiles are small as long as n ED and Q ED are held constant. The results indicate a well-functioning turbine at the best efficiency point and high load. At the part load operating point, a vortex breakdown occurs which distorts the velocity profiles and significantly lowers the turbine's hydraulic efficiency. Frequency spectrums of each LDA signal at part load reveals a peak which is asynchronou...
Print ISSN:
1755-1307
Electronic ISSN:
1755-1315
Topics:
Geography
,
Geosciences
,
Physics
