Numerical simulation of wear particle deposition in ferrograph based on coupled analysis of magnetic, fluid and solid field

Abstract

Ferrography is a significant means of wear particle detection for mechanical equipment. In view of the issue that the wear particle deposition process by a ferrograph is difficult to accurately adjust to avoid accumulation or escape, the deposition behavior of wear particles coupled with the magnetic, fluid and solid field in a ferrograph is studied by the finite element method. The wear particle force and its deposition principle are first analyzed, and the theoretical deposition law is obtained. By building 3D finite element model, setting the magnetic, flow field and wear particle parameters, the coupled simulation based on the particle tracking is carried out. According to the process of wear particles flowing out of the oil tube and then depositing on the ferrogram slide, the effect of oil pressure, viscosity, density, ferrogram slide inclination angle, distance between oil tube and ferrogram slide and the particle release mode on the particle deposition behavior is studied. Based on the velocity and displacement of particles, the reasonable parameter ranges are obtained, and the sensitive variables are determined. In order to verify the numerical law through experiments, the area and perimeter of wear particles are adopted, meanwhile the oil viscosity is selected as the adjustable parameter, and the tested results prove the numerical simulation correct.