导流明渠流速与底宽及流量的非线性关系

建立了用于模拟导流明渠流场的平面二维水流数学模型,采用局部连续非规则网格划分计算区域,有限体积法求解水深积分方程,显式MacCormack预测-校正格式步进计算.利用物理模型的测量数据对数学模型进行验证,数值模拟结果与测量数据吻合较好,表明建立的数学模型能合理地模拟明渠内的水流.通过模拟一系列底宽导流明渠内的流场,得到了底宽一定时明渠最大流速随流量的变化关系,以及流量一定时明渠最大流速随底宽变化的斜率,进而得到了斜率与流量之间的非线性关系,研究成果可为导流明渠的设计提供依据.

Numercial study of nonlinear relationship between velocity and bottom width & discharge in open diversion channel

A 2D numerical model is established with finite volume method;the model is applied to simulate the flow of open diversion channel,computational region was dispersed with portially sequent irregullar mesh,and computation was marching with explicit MacCormack method.To examine the performance of the numerical model,physical model data is used;and the numerical results are in good agreement with the observated data;so the rationality of the numerical model was indicated.The changing slope of maximum velocity with the discharge is obtained via simulation of flow in open diversion channel with a constant width;and the changing slope of maximum velocity with the width is obtained with a constant discharge;consequently,the nonlinear relationship of slope and the discharge is exposed.The research results may provide the basis for the design of the open diversion channel.