水圧脈動特性と流動様式に及ぼす吸出し管幾何形状の影響

概要

論文の詳細を見る
This experimental study treated the characteristics tics of pressure surge and swirl flow in the elbow type draft tube of a Francis turbine at partial load. It was demonstrated that QS type surge or violent pressure fluctuation observed in an original elbow draft tube was the resonant condition entrained by the oscillation of pressure recovery. Thus, a modified elbow draft tube was made to reduce the surge and to improve the turbine stability. Its shape was decided following the concept that an elbow draft tube should be designed so as to secure sufficient pressure rise in the inlet conical-diffuser portion. From the experiments, it is confirmed that QS type surge did not occur in the modified tube. Further, it is found that there is a flow regime where double spiral vortex cores appear intermittently, depending on the cavitation parameter as well as the swirl parameter.
社団法人日本機械学会の論文
1986-09-25