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 order to prevent and eliminate vortex and the vortex tube occurred in the suction passage of two-way-reversible pumping system for the safe operation of the pump unit, an additional curved guide pier was placed on the bottom of suction passage under pump mouth. By using the CFD software the numeric simulation was made to obtain three-dimensional flow fields inside the pumping system with the additional guide pier and predict the performance of the pumping system. Combined with the model test, this paper focused on the velocity distribution of suction passage outlet, and its influences on the pump system performance. Both the computation and the measurement results showed that the additional guide pier on the bottom inside the suction passage did not effect on the velocity distribution of suction passage. The velocity evenness of suction passage outlet reach 93% with guide pier, which can meet the needs of pump operation. The performance of the pumping system was good and the high efficiency of the system at BEP is 68.89%. Experimental observations showed that the set of the guide pier could effectively prevent the vortex generation under pump inlet, the vortices were not found within the suction passage under different operation conditions. The pump ran smoothly without vibration. Comparing the calculated results with the model test results of the outlet velocity distribution of the suction passage, both of them are similar in overall structure and pump performance prediction at BEP is consistent with the test results. 