U形渠道弧顶三角剖面堰的数值模拟

Numerical Simulation of U-Shaped Channel Arc Crested Triangular Profile Weir

为提高三角剖面堰的过流能力,改善其水力特性,提高测流的精确度和可靠性,将堰顶改良形成弧顶三角剖面堰,探究弧顶三角剖面堰的水力特性,为灌区的科学化管理提供科学依据。利用AutoCAD结合GAMBIT软件建立U形渠道弧顶三角剖面堰的基本模型,并进行模拟计算,经过Tecplot软件后处理,从而获得水面线沿程变化规律和流速沿垂直方向的变化规律,得到水头损失最大为0.049 m,小于量水规范要求的5 cm。根据回归分析试验数据得到流量公式,比较渠道流量、模拟流量与计算流量,模拟流量最大相对误差为8.69%,计算流量最大相对误差绝对值为9.75%,三者吻合度较好,说明弧顶三角剖面堰测流精度较高。

In order to improve the flow capacity of the triangular profile weirs, improve the hydraulic characteristics of flow, improve the accuracy and reliability of the flow measurement, it reformed the edge of weir to form arc triangular profile weirs and explored the hydraulic characteristics of the arc triangular profile weirs, for providing scientific basis for the scientific management of irrigation and water control. It established the basic model of U-shaped channel arc triangular profile weirs for numerical simulation by using Auto CAD and GAMBIT software. It obtained the law of water level changes along the river and the variation law of flow velocity along the vertical direction, the obtained maximum head loss was 0.049 m which was 5 cm smaller than that of the standard requirements through post-processing of Tecplot software. Regression analysis of test data obtained flow formula, and compare the channel flow, flow simulation and calculation flow, found that the maximum relative error of simulation flow was 8.69%, the absolute value of maximum error of flow calculation was 9.75%, there was in good agreement, indicating flow measurement precision of arc triangular profile weir was high, having certain practicality and could provide scientific basis for irrigation.