ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

3-D unsteady turbulent flow simulation with RNG k—ε turbulence model of complete flow passage on Francis turbine at partial load condition was performed. The simulation results were compared with the test data. The simulation predicted the pressure fluctuation magnitude and frequency characteristic in the draft tube successfully. A method injecting water from the crown tip to the turbine draft tube to weaken the pressure fluctuation was introduced. Simulation of the flow with water jet was performed, showing that the water jet weakened the pressure fluctuation in the turbine draft tube effectively. With the increase of the jet flow rate, a greater reduction of pressure fluctuation magnitude was detected, but a decrease of efficiency was found. To keep a balance between pressure fluctuation mitigation and efficiency requirement, 0.03~0.05 times of flow rate at the calculated operating condition was suggested.