A coupled model for the multibody dynamics and lubricated joints of internal combustion engines

A coupled model of the multibody dynamics for the main mechanism of internal combustion engines and lubricated joints are developed in this work. The joints are treated as hydrodynamic journal bearings, whose mass-conserving Reynolds equations are solved using the finite element method. The Newton–Euler system of equations of the main mechanism is solved in each time step using the hydrodynamics forces obtained from the lubrication model. Output results of the model including the hydrodynamics forces, maximum oil pressure, minimum fluid thickness, and the orbits are presented for three different crank rotations of an engine. Validation using a conventional lubrication model found in the literature is considered, showing appropriate agreement of results.