An eccentric 3-D fluid-structure interaction model for investigating the effects of rod parallel offset on reciprocating-seal performance

Abstract The rod parallel offset ruins the axial symmetry of reciprocating seals, making the traditional 2-D model inappropriate for quantitative analysis. We propose an eccentric 3-D fluid-structure interaction (FSI) model, comprising the parallel-offset and mixed-lubrication sub-models to investigate the influence of parallel offset on the seal's micro- and macro-performance. Details of the sealing zone, friction and leakage features are analyzed for an O-ring seal at different eccentric distances, system pressures and velocities. Comparisons between the friction characteristics in the mixed-lubrication and dry conditions are also implemented in this paper.