基于无因次相对断面比能规律的台阶式泄槽水面线计算

Calculation of Water Surface Profile of Stepped Chute Based on Dimensionless Relative Specific Energy Law

针对台阶式溢洪道泄槽段沿程断面比能规律复杂且目前水面线计算方法适用范围有限、精度不高等问题,为简化断面比能的复杂规律并由此提出一种可靠的水面线计算方法,在水工模型试验的基础上引入相对断面比能并对其进行因次分析,进而对无因次相对断面比能开展了系统的定性和定量研究。结果表明,无因次相对断面比能的大小与相对临界水深、坡度及无因次位置有关,无因次相对断面比能沿程呈较好的线性相关性;基于定量研究结果给出了无因次相对断面比能计算的经验公式,对其进行整理,进而得出水面线计算的新方法。算例分析表明,所得水面线计算经验公式精度高、适用范围广,可为台阶式泄槽设计提供理论参考和技术支持。

Aiming at the complicated law of specific energy along stepped chute and the low accuracy and limited application scope of current calculation method of water surface profile, a reliable method of calculating water surface profile was proposed. Based on hydraulic model test, this paper introduced the relative specific energy and made dimensional analysis. Then the dimensionless relative specific energy was systematically studied qualitatively and quantitatively. The results show that the dimensionless relative specific energy is related to the relative critical water depth, spillway slope and dimensionless position. The dimensionless relative specific energy has a good linear correlation along the stepped spillway. Based on the quantitative research results, the empirical formula of dimensionless relative specific energy calculation was given, and a new method of water surface profile calculation was obtained. The analysis of numerical example shows that the calculation method of water surface profile has high accuracy and wide application range, which can provide theoretical reference and technical support for the design of stepped chute.