Numerical simulations of oil flow inside a gearbox by Smoothed Particle Hydrodynamics (SPH) method

In this paper, numerical simulations of oil flow inside a gearbox are presented and compared to experimental particle image velocimetry (PIV) results. Instead of a traditional grid-based finite volume method, a mesh-free Smoothed Particle Hydrodynamics (SPH) method is employed. A multi-phase SPH formulation is utilized to resolve the complex multiphase fluid flow. A total of nine simulations are carried out for three oil levels and three Reynolds numbers, to investigate the flow field behavior and to compare with the experimental results. The aeration effect is first considered to qualitatively analyze the quantity and size of bubbles generated due to the rotation of the gears. Furthermore, the velocity field and velocity profile beneath the oil surface are comprehensively analyzed. Our simulation results exhibit physically consistent behavior of the oil flow and good agreement is achieved compared to the experimental results. Flow structures, splashing and recirculation areas are very well captured by the simulation. However, some discrepancies of the velocity field between the numerical and experimental results are also observed, and discussed.