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

In the large flow conditions, the double suction centrifugal pump is susceptible to cavitation damage and has bad operation reliability. Aiming at the problem, a compound impeller with long and short blades was used to improve the cavitation characteristics. By using the shear stress transport (SST) k—ωturbulence model and Rayleigh—Plesset cavitation model, numerical simulation of the double suction centrifugal pump with a conventional impeller and a compound impeller were carried out respectively. The simulation results in the form of characteristic curves were compared with the experimental data, and the internal flow field was analyzed. The result showed that in the large flow conditions, critical net positive suction of the pump with a compound impeller was reduced. Also, the compound impeller can reduce the vapour distribution, change the pressure distribution and improve the dropping flow and backflow. Moreover, the better effect would be achieved under large flow condition.