台阶式溢洪道滑行水流的相对水头  

Relative water head of skimming flow over stepped spillways

作　　者：文明宜 刘韩生[1] 范灵芝[1] 柳思源[1] 

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《排灌机械工程学报》2016年第5期414-417,共4页Journal of Drainage and Irrigation Machinery Engineering

摘　　要：为了研究台阶式溢洪道的消能特性,将台阶溢洪道与光滑溢洪道沿程的总水头进行对比,引入台阶式溢洪道相对水头的概念.通过3个工程的台阶式溢洪道模型试验,坡度为1∶2.0～1∶0.9,台阶高度为0.5～2.0 m,对影响相对水头的主要因素：流程长度、单宽流量、台阶高度、坡度等进行了研究.结果表明,在滑行水流条件下,台阶式溢洪道沿程相对水头小于0;相对水头与流程长度呈良好的线性关系,相关系数为0.998 3～0.999 8;相对水头与单宽流量无关,不同流量条件同一断面的相对水头基本相等,相对误差不超过4.5%,而台阶高度、溢洪道坡度对相对水头影响较大,台阶高度越高、坡度越大,相对水头绝对值越大.试验结果证实了相对水头具有良好的水力规律,便于应用分析,可为台阶溢洪道设计提供参考.In order to study energy dissipation characteristics of stepped spillways,the water head along a stepped spillway is compared with that along a smooth spillway,and a relative hydraulic head concept is introduced. Three engineered stepped spillway models are measured with slope in the range of 1 ∶ 2. 0-1 ∶ 0. 9 and step height ranged in 0. 5-2. 0 m. The effects of length of flow path,unit discharge,step height and slope on the relative head are studied. The experimental results show that the relative head all along the spillway is less than zero,indicating that the flow energy along a stepped spillway is lower than that along a smooth spillway. The relative head has a linear relationship with the length of flow path that is subject to a correlation coefficient between 0. 998 3 and 0. 999 8. The relative head has nothing to do with the unit discharge,as a result,the head in the same section is nearly constant at different discharges with an equal or less than 4. 5% relative error in comparing with the straight line slope. The step height and slope have a great influence on the relative head,especially,the higher the step height and the steeper the slope are,the greater the absolute value of relative head is. The experimental data confirm that the relative head of a stepped spillway varies regularly,and it is convenient for practical application and analysis,and also provides a reference for the design of stepped spillway.

关 键 词：台阶式溢洪道 滑行水流 相对水头 单宽流量 台阶尺寸 坡度 

分 类 号：TV135.2[水利工程—水力学及河流动力学]