直流电力设备表面电致水滴变形现象的数值模拟方法

Numerical Simulation Method for Electro-Induced Deformation of Water Droplets on Surface of DC Power Equipment

电致水滴运动变形是一种涉及电场与流体场相互耦合的复杂物理现象,常见于雨后的绝缘子金具、设备高压均压环表面,高效快速的数值模拟方法是揭示雨滴变形和激发电晕的物理机制的基础。为此针对三维电动流体模型数值计算中常见的计算时间长、收敛困难的问题,从电场唯一性定理出发提出了基于场等效的数值模拟方法,从光偏折原理出发搭建了基于阴影法的水滴变形现象观测平台,通过数值仿真与试验拍摄结果对比的方式验证了该方法的有效性。研究结果表明:本文方法构建的电场与原始电场的相对误差在0.01%以内;数值模拟得到的水滴在正极性直流电压下的喷射形态与试验符合较好,通过比较水滴根部、中部、头部宽度和长度,表明数值模拟和试验的相对误差在10%以内,验证本文模拟方法的有效性,同时在保证收敛性的情况下计算时间由8 h缩短至1 h。

Electro-induced deformation of water droplets is a complex physical phenomenon that involves coupling electric and fluid fields.It is commonly found on the surface of insulator fittings and equipment high-voltage equalizing rings after rain.Efficient and fast numerical simulation methods are the foundation for revealing the physical mechanisms of raindrop deformation and corona excitation.This article addresses the common problems of long calculation time and complex convergence in the numerical calculation of three-dimensional electric fluid models.A numerical simulation method based on field equivalence was proposed.Starting from the principle of light deflection,a water droplet deformation observation platform based on the shadow method is constructed.The effectiveness of this method was verified by comparing numerical simulation and experimental shooting results.The research results indicate that the relative error between the electric field constructed by this method and the original electric field is within 0.01%.The spray morphology of water droplets obtained from numerical simulation under positive polarity DC voltage agrees with the experiment.By comparing the width and length of the water droplet root,middle,and head,it is shown that the relative error between numerical simulation and experiment is within 10%,verifying the effectiveness of the simulation method in this paper.At the same time,while ensuring convergence,the calculation time is reduced from 8 hours to 1 hour.