摘要
基于河流中心稳定点源条件下保守物质等浓度线方程,定义了一种新型Wu’s二参数曲线(异形椭圆)作为隧洞断面内轮廓线,该曲线是由隧洞断面最大高度H和最大宽度W表征的一条完整连续与导数光滑曲线。以压缩系数θ=W/H为判据,给出了H型、标准型和W型异形椭圆的形状分类;推导了异形椭圆无压隧洞断面的水面宽度、过水断面面积、湿周、水力半径等水力要素的理论计算公式;给出的异形椭圆断面流速比和流量比的理论计算公式及曲线适用于不同规格的断面尺寸、压缩系数、糙率和比降。实例分析表明,等效异形椭圆与马蹄形Ⅱ型(带倒角)无压隧洞断面的水力要素特征值吻合程度高;异形椭圆断面可作为一种新型的输水隧洞断面形式,极具学术研究价值。
To define the inner outline of a tunnel cross-section,a novel Wu’s two-parametric curve(heteromorphic ellipse)was proposed in this study,based on the iso-concentration curve equation of a conservative substance under the condition of steady point source from river center.The heteromorphic ellipse is a completely continuous and derivative-smooth curve,represented by the maximum height(H)and the maximum width(W)of the tunnel cross-section.Taking the compressibility factorθ=W/H as the criterion,the shape classification of H-type,Standard-type and W-type for the heteromorphic ellipse were given.The cross section,the theoretical calculation formula of water surface width,flow area,wetted perimeter,hydraulic radius and other hydraulic elements were deduced for the free-flow tunnel.The theoretical calculation formulas and curves for the velocity and the flow rates were found to be applicable to different specifications of the cross-section size,compressibility,roughness and gradient.Case studies show that the characteristic values of hydraulic elements have a high degree of anastomosis for the equivalent heteromorphic ellipse and theⅡ-type horseshoe(with chamfer)cross-section in a free-flow tunnel.Therefore,the proposed heteromorphic ellipse cross-section can be a novel application in water-conveyance tunnels with great academic research value.
作者
武周虎
王瑜
祝帅举
WU Zhouhu;WANG Yu;ZHU Shuaiju(School of Environmental and Municipal Engineering,Qingdao University of Technology,Qingdao 266033,China;Henan Urban and Rural Planning and Design Institute Co.,Ltd.,Zhengzhou 450044,China)
出处
《水利水电科技进展》
CSCD
北大核心
2020年第5期1-8,共8页
Advances in Science and Technology of Water Resources
基金
国家自然科学基金(51379097,50979036)。
关键词
水工隧洞
二参数曲线
异形椭圆
断面标准方程
几何特征
水力要素
无压均匀流计算
hydraulic tunnel
two-parameter curve
heteromorphic ellipse
cross-section standard equation
geometric characteristics
hydraulic elements
calculation of non-pressure uniform flow
