Study on Energy Dissipation Characteristics of Skimming Flow on Stepped Spillways

臺階式溢洪道滑行水流消能特性之研究

馬朋輝(PENGHUI MA) ； 胡亞瑾(YAJIN HU) ； 劉韓生(HANSHENG LIU)

《台灣水利》 69卷2期 (2021/06) Pp. 89-102

https://doi.org/10.6937/TWC.202106/PP_69(2).0008

摘要

Stepped spillway has attracted the attention of the hydraulic engineering researchers and has been widely studied and applied for its remarkable energy dissipation effect, greatly reducing the size of stilling basin at the end of the spillway, saving engineering quantity and investment. In order to reflect the increased energy dissipation effect of steps on stepped spillways, this paper compared stepped spillways with smooth spillways of the same shape, and introduced the concepts of step energy dissipation rate and step energy dissipation head ratio. Based on the hydraulic model test of Simutasi Hydropower Station, the variation characteristics of the total energy dissipation rate, smooth energy dissipation rate, step energy dissipation rate and step energy dissipation head ratio along the way and their relationship with the relative critical water depth were systematically analyzed. It was revealed that the decrease of the total energy dissipation rate of the stepped spillway with the increase of the discharge per unit width (or relative critical water depth) is caused by the decrease of the smooth energy dissipation rate while the step energy dissipation rate remains unchanged. The research results have important practical significance for understanding, analyzing and applying stepped spillways.

關鍵字

Stepped spillway ； Experimental study ； Total energy dissipation rate ； Smooth energy dissipation rate ； Step energy dissipation rate ； Step energy dissipation head ratio

並列摘要

臺階式溢洪道由於消能效果顯著、能大大減小溢洪道末端消力池的尺寸、節省工程量和投資而引起水利工程界的重視，並得到較為廣泛的研究和應用。為了反映臺階式溢洪道中臺階所增加的消能作用，本文將臺階式溢洪道和同體型的光滑溢洪道進行對比，引入了臺階消能率和臺階消能水頭比。通過斯木塔斯水電站水工模型試驗，系統分析了臺階式溢洪道總消能率、光滑消能率、臺階消能率及臺階消能水頭比沿程變化規律及其與相對臨界水深的關係，並且揭示了臺階式溢洪道總消能率隨單寬流量（或相對臨界水深）的增大而降低是由於臺階消能率不變而光滑消能率降低所導致的。研究結果對於認識、分析和應用臺階式溢洪道具有重要的現實意義。

並列關鍵字

臺階式溢洪道 ； 試驗研究 ； 總消能率 ； 光滑消能率 ； 臺階消能率 ； 臺階消能水頭比