基于数值模拟的风生流场的量化特性及参数优化分析

Quantitative Characteristics and Parameter Optimization Analysis of Wind-driven Current Based on Numerical Simulation

为研究风生流场的量化特性,数值模拟了矩形水槽风生流场,分析了风生流数值模拟中风应力拖曳系数和垂向紊动粘性系数两个主要参数的误差。结果表明,风生流场垂向流速分布呈抛物线形,断面平均流速为零,流速回旋中心位于水深1/3处,存在最大正向流速和最小反向流速且流速比为2.41。通过分析风应力拖曳系数和垂向紊动粘性系数误差对数值模拟结果的影响,研究了快速实现风生流数值模拟参数优化的方法。对香溪河流速分布的模拟分析,验证了该流速中存在风生流场,且通过参数优化方法快速实现了风生流参数的优化,与实测值对比表明该方法的精度较高。

To study the quantitative characteristics of wind-driven current,based on numerical simulation of rectangle flume wind-driven current,the deviation of two main parameters is analyzed in the wind stress drag coefficient and vertical turbulence viscosity coefficient.The results show that the distribution of vertical velocity is a parabola in wind-driven current and the mean velocity of cross-section is 0.The velocity slalom center locates at a third of water depth.There are maximum forward velocity and the minimum reverse velocity in the cross-section and the ratio of them is 2.41.This paper studied the rapid optimization method of numerical simulation parameters of wind flow in wind-driven current through the analysis of influence which come from the deviations of the wind stress drag coefficient and vertical turbulence viscosity coefficient on numerical simulation results.The wind-driven current is found to be existed through the analysis of velocity distribution of Xiangxi River in numerical simulation.The optimization of wind-driven current's parameter is rapidly optimized by using the parameter optimization method.The accuracy of the method is higher by comparison the numerical simulation value with the measured value.