面积收缩比相同条件下不同体型齿墩式内消能工对管道内部水力特性的影响

Effect of Different Body Types of Toothed Energy Dissipaters on Interior Hydraulic Characteristics of Pipeline under the Same Area Contraction Ratio

为研究同一面积收缩比情况下不同体型齿墩式消能工对管道内部水力特性的影响,采用物理模型试验与理论分析相结合的方法,分析了5种方案消能工的消能率、过流能力、时均压强和脉动压强的变化特征。结果表明,面积收缩比相同时,方案3消能率最小,齿墩高度比不等于0.5时消能率随齿墩高度增加而增大,流量系数的变化规律则相反;时均压强系数在消能工进口处骤降,并在距离消能工进口4 D处逐渐恢复至稳定,但比消能工进口处低2.5~2.8,表明齿墩高度比对时均压强系数影响较小;脉动压强系数沿程基本呈双峰分布,双峰分别位于消能工进口和出口附近,第二个峰值最大值及最小值分别是方案2、3。综合分析后知方案2最佳,为推荐方案。

In order to analyze the impact of different body types of the toothed energy dissipaters on the hydraulic characteristics in the condition of the same area shrinkage ratio,the energy dissipation rate,flow capacity and pressure characteristics are studied by the method of physical model tests and theoretical analysis.In the condition of the same area shrinkage ratio,the results show that energy dissipation rate is the smallest for the scheme 3 and increases with the height ratio of toothed piers(hr)when the height ratio of toothed piers is not equal 0.5.The change law of flow coefficient is opposite to that of energy dissipation rate.The time-average pressure coefficient drops sharply at the entrance of energy dissipater,and gradually recovers stable in the position of 4D,where its value is less 2.5-2.8 compared with that in inlet section of testing pipe,and the height ratio of toothed piers has less impact on the time-average pressure coefficient.The pulsating pressure coefficient has a bimodal distribution along the path,the first peaks are located behind the inlet of toothed energy dissipater,and the second peak appears after outlet of the toothed energy dissipater.In addition,the largest and smallest value of the second peak is scheme 2 and scheme 3,respectively.Based on the comprehensive analysis of the results,the scheme 2 is a better option.