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 principle to determine the orifice area of spool valve with two-stage notches was proposed based on the series parallel effects of fluid flowing in channel of the notches. The formulas to calculate the orifice area were obtained and the corresponding computational program was worked out. Then, the experimental results on the flow characteristic of two-stage notches were analyzed. The results show that the flow coefficient of two-stage notch is the combination of that of each single notch. When the spool displacement was small or near to full open, the flow coefficient increased quickly. At the middle part of displacements, the flow coefficient was about 0.7～0.8. The flow coefficient in flow-out direction was larger than that of flow-in, which was about 0.1. A new concept of orifice area of flow control for defining the flow control function of the orifice was proposed. 