Mixed Lubrication Modeling of Reciprocating Seals Based on a Developed Multiple-Grid Method

Abstract

Nonconvergence is a frequent problem for mixed lubrication modeling of reciprocating seals, which couples a finite element analysis (FEA) commercial software with the fluid–structure interaction (FSI) procedure. Local refinement of the contact zone helps convergence, but this is time-consuming and requires extra skills for the mesh procedure. This article presents a mixed lubrication model based on a developed multiple-grid method to investigate the combined seal at different system pressures. This method does not require local refinement of the sealing zone. The position of the start point of the sealing zone changes and is renewed after the film thickness computational procedure. To avoid resolving unreasonable equations during the iteration, the cavitation state was updated with the relaxation of the cavitation length rather than the cavitation index parameter. The frictional performance of the combined seal with a backup ring at different system pressures was analyzed and compared with the experiments. The results of the simulation agree with the experimental results.