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

A series of pressure fluctuation and vibration acceleration were measured at the key monitoring points under the speeds of 1450, 1200, 1000r/min, and their correlations were discussed. The experimental results showed that the peak to peak values of the pressure fluctuation didn’t obey the pump similarity law. The pressure fluctuation patterns were different under different rotating speeds. The maximum peak-to-peak value moved from the impeller inlet to the guide vane outlet with the rotating speed increased. The main frequency at impeller inlet was the blade passing frequency (BPF) under different rotating speeds, and the main frequency in impeller outlet and guide vane outlet were slightly lower than the blade passing frequency with rotating speed increased. The amplitude at the impeller outlet was increased firstly, and then decreased, while it was always increased at the guide vane outlet with rotating speed increased. The vibrations at different positions in the model pump mainly included shaft frequency which was induced by mass unbalance of rotor system and the low frequency induced by the unsteady fluid in pump. In the frequency ranged from about 0 to 2 times,，the pressure pulsation and vibration tendency was substantially the same, and the speed variations had a similar effect on both of them. There were main 1~4 times rotation frequencies in pressure fluctuation frequency domain at different monitoring points, which were changed under different rotating speeds, while only 1 and 2 times of shaft rotation frequency played the main role in the vibration frequency domain at different monitoring locations.