A blended CFD/multi-body analysis method for elastohydrodynamics of plastic oil pan

In this paper, a computational fluid dynamics (CFD) and finite element multi-body analysis blending method is proposed to analyze the dynamic characteristics of oil pan and the hydrodynamic/structural factors affecting camshaft speed fluctuations. With CFD approaches, the oil-air two-phase flows in plastic pan on different time scales are simulated, and the evolution processes of oil in an oil-air two-phase system with gravitational load are depicted. Therefore, the structural dynamic properties influenced by oil flow on the surface of oil pan can be obtained via finite element multi-body analysis. By coupling the fluid viscosity effect and elastic deflection of solid contacting surfaces, the noise, vibration and harshness(NVH) performance are well demonstrated. In this way, the mechanical influences of thin-walled parts of the diesel engine are calculated and analyzed. Numerical results show the fluid-structure response at idle speed and reflect its mechanical essence. With the fluid dynamical and structural dynamical pictures, the characteristics of oil pan and advantages of specific designations are proved, which provides the key factors of NVH performance and emerging design principles.