Collision Mechanism and Deposition Characteristics of Particles on the Catenary Insulator Surface

Abstract

To solve the problem of contamination flashover of a catenary insulator in an electrified railway, the collision mechanism and deposition characteristics of contamination particles on the insulator surface should be studied to ensure the safe operation of traction power supply systems. This research used horizontal and oblique cantilever insulators as objects, and established the collision model between particles and insulator surface under different arrangements. The deposition conditions of particles on the insulator surface were obtained, and the simulation model of insulator contamination accumulation was established by using the Euler two-phase flow. The difference of contamination deposition characteristics between horizontal and oblique cantilever insulators was analyzed with the volume fraction of contamination particles as the characterization parameter. By comparing the cantilever insulator with the positive feeder insulator, this study analyzed the influence of shed structure on the contamination deposition characteristics. Results show that the installation method of an insulator has an impact on the contamination deposition on the insulator surface. When particle size and wind velocity are fixed, the degree of contamination accumulation on the surface of the oblique cantilever insulator is constantly higher than that of the horizontal cantilever insulator. The insulator shed structure also has a certain effect on the contamination deposition on the insulator surface. For the cantilever insulator, the degree of contamination accumulation of the windward side is higher than that of the leeward side. However, for the positive feeder insulator, the degree of contamination accumulation of the windward side is consistently less than that of the leeward side. Measures to deal with contamination flashover of catenary insulator are proposed.

A Note on the Influence of Smectite Coating on the Coefficient of Restitution of Natural Sand Particles Impacting Granitic Blocks

“…The study of the interactions of particles and between particles and blocks is of major interest in geotechnical and petroleum engineering applications, such as the examination of debris flows [1,2], the collision behavior of particles/fragments with protective barriers [3][4][5], or the examination of the contact behavior of proppants and between proppants and rocks in the hydraulic fracturing process [6,7]. Impact problems are also of major interest in industrial processes and pharmaceutical applications [8][9][10]. Previous experimental studies have predominantly examined these interactions by measuring and modeling the frictional behavior of the interacting grains (or grain-block systems) [11][12][13], the damage behavior of proppants [6,7,14], and by examining the influence of sand particle (and rock) type and their morphological features such as surface roughness [15,16] and grain shape [12,13,17].…”