4mm虹吸管高扬程虹吸流速研究（英文）
发布时间：2018-11-17 10:59
【摘要】：目的:探索高扬程条件下4mm虹吸管内气体集聚现象对虹吸流速的影响,并对传统虹吸流速水力学计算公式进行修正。创新点:1.通过对比物理模型实验值和计算值,得出了高扬程虹吸流速的控制因素及传统虹吸流速计算公式在高扬程条件下的不适用性;2.通过分析实验数据,对有压管流水力学公式进行修正,使之适应高扬程条件下的虹吸流速计算。方法:通过物理模型试验,揭示高扬程虹吸流速的特征(图3);将高扬程虹吸流速实验值和传统虹吸流速水力学公式计算值进行对比(表3和4);通过分析实验数据,结合有压管流水力学公式,得出高扬程虹吸流速经验公式(公式(5)和(8))。结论:1.在高程差H_1一定时,虹吸流速与扬程呈负相关;在扬程H0一定时,虹吸流速随高程差H_1的增大而流速加快,直至达到最大流速,并保持稳定状态;虹吸流速与管长呈负相关。2.高扬程虹吸排水由于管内气压降低析出大量气泡,形成气液二相流,影响虹吸流速的计算;目前采用的有压管流水力学计算公式不适用高扬程4mm虹吸管的虹吸水流。3.当H_12ΔH,虹吸流速的控制因素为高程差H_1;当H_1≥2ΔH,虹吸流速的控制因素为当地虹吸极限扬程H_(max)和H_0的差值ΔH;4.对于高扬程4mm虹吸管虹吸流速的确定,一是可以直接实验测定,查找相关数据,二是可以采用经验公式来确定相关的虹吸流速。
[Abstract]:Aim: to investigate the effect of gas accumulation in 4mm siphon on siphon velocity under high lift conditions, and to modify the traditional formula of siphon velocity hydraulic calculation. Innovation: 1. By comparing the experimental and calculated values of the physical model, the control factors of the high head siphon velocity and the inapplicability of the traditional siphon velocity calculation formula under the condition of high head are obtained. 2. By analyzing the experimental data, the mechanics formula of pressurized pipe flow is modified to adapt to the siphon velocity calculation under the condition of high head. Methods: the characteristics of high head siphon velocity were revealed by physical model test (Fig. 3), and the experimental values of high head siphon velocity were compared with those calculated by traditional siphon velocity formula (tables 3 and 4). By analyzing the experimental data and combining the pressure pipe flow mechanics formula, the empirical formulas of high head siphon velocity (5) and (8).) were obtained. Conclusion: 1. The siphon velocity is negatively correlated with the head when the elevation difference H _ 1 is fixed, and the siphon velocity increases with the increase of the height difference H _ 1 until the maximum velocity is reached, and the state of the siphon velocity remains stable. The siphon velocity was negatively correlated with the tube length. 2. A large number of bubbles are released from high head siphon drainage due to the reduction of air pressure in the pipe, which results in gas-liquid two-phase flow, which affects the calculation of siphon velocity, and the current calculation formula of pressure pipe flow mechanics is not suitable for siphon flow of high head 4mm siphon pipe. When H12 螖 H, the control factor of siphon velocity is elevation difference H _ 1, and when H _ 1 鈮，
本文编号：2337533
[Abstract]:Aim: to investigate the effect of gas accumulation in 4mm siphon on siphon velocity under high lift conditions, and to modify the traditional formula of siphon velocity hydraulic calculation. Innovation: 1. By comparing the experimental and calculated values of the physical model, the control factors of the high head siphon velocity and the inapplicability of the traditional siphon velocity calculation formula under the condition of high head are obtained. 2. By analyzing the experimental data, the mechanics formula of pressurized pipe flow is modified to adapt to the siphon velocity calculation under the condition of high head. Methods: the characteristics of high head siphon velocity were revealed by physical model test (Fig. 3), and the experimental values of high head siphon velocity were compared with those calculated by traditional siphon velocity formula (tables 3 and 4). By analyzing the experimental data and combining the pressure pipe flow mechanics formula, the empirical formulas of high head siphon velocity (5) and (8).) were obtained. Conclusion: 1. The siphon velocity is negatively correlated with the head when the elevation difference H _ 1 is fixed, and the siphon velocity increases with the increase of the height difference H _ 1 until the maximum velocity is reached, and the state of the siphon velocity remains stable. The siphon velocity was negatively correlated with the tube length. 2. A large number of bubbles are released from high head siphon drainage due to the reduction of air pressure in the pipe, which results in gas-liquid two-phase flow, which affects the calculation of siphon velocity, and the current calculation formula of pressure pipe flow mechanics is not suitable for siphon flow of high head 4mm siphon pipe. When H12 螖 H, the control factor of siphon velocity is elevation difference H _ 1, and when H _ 1 鈮，
本文编号：2337533
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