非结构网格数值模拟映射的河流能量公式推导及探析

Derivation and Analysis of River Energy Formula for Unstructured Grid Numerical Simulation Mapping

河流能量体现河流活力,其分布特征反映了河流变化调整规律。为研究河流全河段的能量分布特征,分析了基于计算流体力学理论的河流能量(机械能)组成与计算方法,探讨了基于非结构网格的单元河流能量表达式以及考虑河床变形的总能量调整控制条件,采用MIKE21软件对概化后的顺直河段非结构网格单元体系下的水流质量通量进行了守恒性验证,并对全河段的河流能量进行了计算。结果表明:应用流量公式校验得到的模拟河段流量满足守恒条件,推导的能量公式可用于精细计算非结构网格单元体系下的河流能量,并且可得到河流全河段能量的分布状况。该研究可为基于能量分布的河流研究提供一种新的思路和方法。

River energy reflects the vitality of the river,and its distribution characteristics reflect the adjustment law of river change.In order to study the energy distribution characteristics of the whole river section,this paper analyzes the composition and calculation method of river energy(mechanical energy)based on computational fluid dynamics theory,and discusses the unit river energy expression based on unstructured grids and the control condition of total energy adjustment considering the riverbed deformation.In this paper,the MIKE21 software is applied to verify conservation of water flow mass flux under unstructured grid system after generalized straight channel,and the river energy of the whole river section is calculated.The results are as follows.The simulated river flow obtained by using the flow formula satisfies the conservation condition.The derived energy formula can be used to calculate the energy of the river in the unstructured grid system,and the energy distribution of the whole river can be obtained.This study can provide a new idea and method for the study of rivers based on energy distribution.