摘要
目前明渠水面线计算中各常规方法普遍存在过程繁琐、应用不便的问题,从明渠渐变流基本微分方程出发,研究简便直接的计算方法是可行必要的。根据标准城门洞形断面的几何特征,推导出断面不同水深的水力参数计算式。通过无量纲化处理和优化拟合理论,将渐变流基本方程转化为通用函数积分表达式,得到了直接计算标准城门形隧洞水面线的积分公式。通过算例比较分析,直接计算方法计算方便,其与分段试算法的最大误差小于0.64%,计算精度完全满足工程应用需要。
The common calculation methods of water surface profile for open channel flow are universal existence of complicated process and inconvenient application.It is necessary and feasible to work out a simplified calculation method for engineering application based on the basic differential equation of gradually varied steady channel flow.According to geometrical shape of standard city-gate cross section,the formulas for calculating hydraulic factors with different water depths were derived.Through dimensionless treatment and optimization fitting theory,the basic equation of gradual flow is transformed into general function integral expression,and then the integral formula for direct calculating water surface profile of standard city-gate cross section tunnel was given.Through the comparison and analysis of examples,the direct integral method has advantages of highprecision and convenient calculation,its calculation accuracy meets the requirement of engineering application.The maximum error of direct integral method is less than 0.64%compared with the trial-and-error method.
作者
班国德
牛坤
BAN Guo-de;NIU Kun(Pingyi Country Agriculture and Rural Affairs Bureau,Pingyi 273300,China)
出处
《云南水力发电》
2020年第8期120-123,共4页
Yunnan Water Power
关键词
标准城门洞形隧洞
水力要素
恒定渐变流
水面线
计算方法
standard city-gate tunnel
hydraulic factors
constant gradual flow
water surface profile
calculation method
