多ノズルペルトン水車のジェット干渉 : 第3報, 自由ジェットの流速減衰モデルを用いた切欠き流れ強さの予測

概要

論文の詳細を見る
Jet interference causes serious deterioration of efficiency in multi nozzle Pelton turbines especially in the operating region of low energy coefficients and high discharge coefficients. Since the jet interference is intensified by the scale effect, it is difficult to predict the jet interference of a prototype only from its low-head model test results without consideration of the scale effect. Therefore, theoretical approaches for predicting prototype jet interference are urgently required. In the present study, the scale effect of specific energy on jet interference is investigated using the relative jet paths with the velocity deceleration model of a free jet, in which scale effects in the free jet due to the internal friction, the entrainment of water droplets into the jet and the domino effect based on the discharge from the cutout of the buckets are considered. The predicted intensity of the discharge from the cutout shows a good correlation with the deterioration of efficiency due to the jet interference.
1999-02-25