平底悬链线形明渠水力最优断面求解  

Optimal hydraulic section of horizontal-bottom catenary channel

作　　者：韩延成 梁梦媛 Said M Easa 唐伟 初萍萍 高学平[3] Han Yancheng;Liang Mengyuan;Tang Wei;Chu Pingping;Gao Xueping(School of Water Conservancy and Environment,University of Jinan,Jinan 250022,China;State Key Laboratory of Hydraulic Engineering Simulation and Safety,Tianjin University,Tianjin 300072,China)

机构地区：[1]济南大学水利与环境学院,济南250022 [2]Department of Civil Engineering,Ryerson University [3]天津大学水利工程仿真与安全国家重点实验室,天津300072

出　　处：《农业工程学报》2019年第6期90-99,共10页Transactions of the Chinese Society of Agricultural Engineering

基　　金：山东省自然科学基金(ZR2017LEE028);山东省"一事一议"(周飞艨)人才计划项目;山东省重点研发计划(2016GSF117038);国家"十二五"科技支撑计划(2015BAB07B02-6)

摘　　要：断面设计是渠道设计的重要内容之一,适宜的渠道断面不仅能够增加过流能力,提高输水效率,减小输水损失,还能降低建造成本。该文提出了一种具有平底和悬链线形侧边的明渠断面。这种断面将平底和悬链线侧边平滑连接,既具有平底断面建造容易、灵活,管护方便,底部容易压实,侧边和平底可以用不同材料建造(以降低成本)等优点,也具有悬链线形断面过流能力大、无应力集中拐角、不宜渗漏、防冻胀能力强,耐久性好等优点,可广泛应用于大、中、小型渠道及寒区,具有良好的实用价值。推导了过流面积、湿周、水面宽度等水力断面特性计算公式。提出了一个更简单的正常水深的迭代算法。基于拉格朗日乘子法,推导出了平底悬链线形明渠的水力最优断面,结果表明其水力最优断面的底宽与水深比、水面宽与水深比、底宽与形状系数比、水面宽度与形状系数比、形状系数与水深比均为常数:宽深比等于0.405,形状系数与水深比等于0.474,水面宽与水深的比值为2.112,底宽与形状系数的比值为0.855。与现有平底断面(梯形、平底抛物线形、平底半立方抛物线形)进行了比较,结果表明,在过流面积或湿周一定的情况下,平底悬链线形断面的过流能力最大,相反,在流量一定的情况下,平底悬链线形断面的过流面积、湿周、水面宽度是最小的。与传统的悬链线形渠道进行了比较,增加平底后,在同等条件下,平底悬链线形渠道水力最优断面的过流能力不仅没有降低,反而增加了,意味着其经济性也优于传统的悬链线断面。研究为平底悬链线形渠道设计提供理论支撑。A suitable channel section cannot only increase flow capacity of channel,improve efficiency of water resources,and reduce water leakage loss,but also decrease construction cost.This paper proposed a channel section with a horizontal bottom and catenary sides(HBC).The HBC section,on one hand,provided a larger flow capacity,lesser-sharp angles of stress concentration,less leakage,better slope stability and frost heave resistance than trapezoids and rectangles sections.On the other hand,it had lots of advantages of horizontal bottom sections,such as simpler construction,easier leveling and compaction of the foundation,and lesser construction cost.The most important advantage of this section was that the horizontal bottom and sides could be built with different materials or thickness for decreasing the construction cost or other purposes.The shape function for HBC was defined.The formulas for the flow area,wetted perimeter,and water surface width were presented.A simpler iterative algorithm for calculation of the normal depth was developed.The iterative convergence by this algorithm was evidenced.Comparisons showed that this simpler iterative algorithm was better than classic Newton iterative algorithm.The optimal model of the best hydraulic section of HBC was built.The general differential equations for all the sections having horizontal bottomed and curve sides were derived.The best hydraulic section of HBC channel was obtained according to Lagrange multiplier method and its characteristics were presented including shape factor,ratio of horizontal bottom width to shape factor etc.The results showed that the following optimum parameters were constant for the best hydraulic HBC section:bottom width to water depth,water surface width to depth,bottom width to shape factor,water surface width to shape factor,shape factor to water depth equals.The ratio of water surface width for catenary part to shape factor equaled 3.602,the ratio of bottom width to shape factor equaled 0.855,the ratio of bottom width to water depth eq

关 键 词：形状 水力学 渠道 平底 悬链线形 水力最优断面 

分 类 号：TV131.4[水利工程—水力学及河流动力学]