复式河槽过流能力非线性研究

传统方法不能准确预测复式河槽过流能力。针对这一不足，本文采用系统动力学方法探寻复式河槽过流能力的计算。通过分析英国科学工程研究协会洪水水槽设(SERC-FCF)的大量的系列水槽实验成果，发现滩槽Darcy-Weisbach阻力系数比值随着相对水深的增加而减小。主槽阻力系数随着相对水深的变化而变化，呈抛物线分布。根据获得的阻力系数关系，运用系统动力学方法，建立了洪水漫滩后，复式河槽过流能力的系统动力学模型。计算结果表明：该模型能确定水位流量关系，其模拟值与实测值吻合较好，其相对误差的绝对值仅在3％左右。

A Nonlinear Study of Conveyance Capacityin Compound Channels

The conventional methods cannot correctly predict discharge in a compound channel.Aiming at the shortcoming,the paper adopts system dynamics method to study the conveyance capacity.By analyzing a vast number of experimental data from Science and Engineering Research Council Flood Channel Facility (SERC-FCF),it is found that the ratio of the Darcy-Weisbach resistance coefficients between on the flood plain and in the main channel decreases with the relative depth increasing. The resistance coefficient in the main channel varies with the relative depth and follows the paraboloidal distribution. On the basis of the resistance coefficient relationships obtained, applying system dynamics method, the authors established the system dynamics model of conveyance capacity when water flows in an out-of-bank manner and onto the adjoining flood plain. The model gives the relationship between stage and discharge.There is a good agreement with modeled and experimental values.The absolute values of the relative errors of discharge are very about 3%.