台阶式溢洪道消能规律  

Energy dissipation pattern of stepped spillways

作　　者：杨吉健[1] 刘韩生[1] 张峰[2] 文明宜 安梦雄[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 [2]中国电建集团贵阳勘测设计研究院有限公司,贵州贵阳550081

出　　处：《排灌机械工程学报》2015年第2期123-127,共5页Journal of Drainage and Irrigation Machinery Engineering

摘　　要：为探讨台阶式溢洪道消能特性及水流的紊乱特性规律,将台阶式溢洪道与对应光滑溢洪道对比研究,通过试验数据计算出台阶式溢洪道消能率、阶顶断面弗劳德数,试算求出对应光滑溢洪道水力参数,用台阶式溢洪道消能率减去对应光滑溢洪道消能率得到相对消能率,光滑溢洪道断面弗劳德数减去对应台阶式溢洪道阶顶断面弗劳德数得到相对弗劳德数.两水力参数反映了台阶式溢洪道相对光滑溢洪道对消杀能量大小及水流紊乱剧烈程度.通过对26.57°,32.01°,33.69°,38.66°,51.3°这5组不同坡度,1.43~6.67 cm台阶高度的21组模型试验研究,探讨了相对消能率和相对弗劳德数之间关系,结果表明相对弗劳德数和相对消能率沿程呈线性关系,相关系数为0.993 7~0.999 5.且相同相对弗劳德数,单宽流量大对应相对消能率也大;台阶高度变化对直线关系影响很小;坡度对直线关系影响复杂,较小坡度同一单宽流量,坡度越大相对消能率越小,坡度较大时同一单宽流量,坡度大对应相对消能率大.相对消能率和相对弗劳德数的直线规律体现出台阶式溢洪道独特的水力特性,为探究其消能机理提供了重要依据.Self-aerated stepped spillways are widely used for high energy dissipation ratio and less investment. In order to reflect the whole energy dissipation characteristics,and the disorder of flow,the concepts of relative energy dissipation ratio and relative Froude number of stepped spillways after comparing the energy dissipation ratio and Froude number of stepped spillways and corresponding smooth spillway were introduced,of which the relative energy dissipation is the difference between the stepped spillways and corresponding smooth spillway,and the relative Froude number is the difference between the smooth spillway and corresponding stepped spillways. These two hydraulic parameters reflect the ability of stepped spillways to the energy of flow and the disorder of flow,which are different from smooth spillway. Twenty-one groups of tests on stepped spillways with 26. 57°,32. 01°,33. 69°,38. 66° and 51. 3°five different chute angles,1. 43- 6. 67 cm step heights were conducted,and the results shows the linear correlation coefficient between them is 0. 993 7- 0. 999 5. The major width unit has major energy dissi-pation ratio with the same relative Froude number; the step height has little effect on the linear relation;and the slope has a complex effect on the linear relation,the major slope has minor Froude re-lative energy dissipation ratio when the slope is minor,however,the minor slope has minor Froude relative energy ratio when the slope is major. The law reflects the hydraulic characteristics of stepped spillway,and provides an important theory for further exploring the mechanism of energy dissipation.

关 键 词：自掺气台阶式溢洪道 相对消能率 相对弗劳德数 线性关系 

分 类 号：TV135.2[水利工程—水力学及河流动力学]