Scale effect on actual Euler's head in hydraulic turbomachinery

摘要

The effect of difference between discharge flow angles from model runners and prototype ones on the actual Eulers head and the efficiency of hydraulic turbo-machines are discussed by using the scale effect formula used at present. Then discharge flow angles from the flat plate cascades similar to the runner vanes of models and prototypes are decided under consideration of boundary layer thickness which changes with Reynolds number and surface roughness.