Abstract:

In order to increase the specific speed and force of Pelton turhines , the multi-nozzle confìguration is commonly adopted. However , the addition of nozzles leads to the jet interference , which reduces the efficiency of Pelton turhines. In this paper , the reasons for jet interference are analyzed. By calculating the numhers of four kinds of threshold frames , that is , the frame when the hucket meets the next jet , the frame for the last capture of
outermost streamline of jet hy a hucket , the frame for the occurrence of ineffective jet hy non-capture and the frame at the cross point of two jets , two criteria are presented to predict the occurrence of interference for two adjacent hare jets. The criteria are then used to predict the hare-jet interference in the Pelton turhines with different nozzles and huckets , whose effectiveness is finally verified hy the predicted results.

Key words: Pelton turhine, jet interference, multiple nozzle, hucket, Computational Fluid Dynamics