标准Ⅰ型四圆弧蛋形断面的水力计算

Hydraulic calculation of standard type-I four arcs egg-shaped cross section

提出了标准Ⅰ型四圆弧蛋形断面正常水深、临界水深、水跃共轭水深、水面曲线的计算方法。依据标准Ⅰ型四圆弧蛋形断面的形式,根据几何图形研究其水力参数的计算公式,包括断面面积、水面宽度、湿周、断面形心距水面距离的计算公式;根据明渠均匀流和明渠恒定非均匀流的基本理论,研究标准Ⅰ型四圆弧蛋形断面的正常水深、临界水深、水面曲线的计算方法;根据明渠水跃的基本方程研究标准Ⅰ型四圆弧蛋形断面水跃共轭水深计算方法;给出了标准Ⅰ型四圆弧蛋形断面水力参数的计算公式以及正常水深、临界水深、水跃共轭水深的简单计算公式和水面曲线的积分计算公式。通过三个算例进行验证,结果表明:本文提出的正常水深、临界水深、水跃共轭水深的简化计算公式与理论计算公式相比,误差分别为0.049%、0.0082%、0.35%;水面线的积分算法与步高为1mm的分段算法相比,误差为0.816%。表明了本文计算方法的准确性。

The calculating method of normal depth, critical depth, the conjugate depth of hydraulic jump and water surface profile of standard type-I four arcs egg-shaped cross section are investigated. According to the form of standard type-I four arcs egg-shaped cross section, cross section area, surface width, wetted perimeter, the section centroid distance above the water are researched, on the basis of the theory of open channel uniform and non-uniform flow, calculation method of normal water depth, the critical depth and surface curve of standard type-I four arc egg-shaped section are studied, according to the basic equation of open channel hydraulic jump, calculation method of hydraulic jump is presented. Calculation formula of hydraulic parameters, simple computational formulas of normal depth, critical depth and conjugate water depth of hydraulic jump and integral formula of water surface profile are given. Compared with the theoretical calculation formula by three examples, the errors of simplified calculation formula of normal depth, critical depth and conjugate water depth of jump are 0.049%, 0.0082% and 0.35%, respectively, compared with segmentation algorithm with 1mm step high, the error of integral algorithm of water line is 0.816%.