Analysis of the cavitation mechanism of the oil film in the main bearing of the diesel engine under dynamic load

To reveal the generation mechanism of oil-film cavitation in the main bearing of diesel engines under dynamic load, this paper adopts large eddy simulation combined with overlapping mesh technology, considers the correction of physical property parameters of lubricating oil under high pressure and high temperature, realizes the transient calculation of the three-phase flow field of bearing bush oil film under dynamic boundary conditions, and verifies the accuracy of the calculation method through experiments. The results show that the cavitation of the main bearing oil film in diesel engines mainly comes from three types of mechanisms: high-speed jet cavitation caused by the contraction of the flow channel when the journal oil hole passes the end of the oil groove, the gradually shrinking and gradually expanding flow channel cavitation caused by journal eccentricity, and the instantaneous negative pressure cavitation resulting from journal radial displacement.