A Numerical and Experimental Study of the Effect of Aeration of Oil on Valve Trains Equipped with Hydraulic Lash Adjusters

A model of a valve train equipped with a direct acting hydraulic lash adjuster (HLA) is presented. Possible aeration of oil in the HLA is taken into account. Moreover the evolution of the aeration in the HLA, due to dissolution and to aeration of oil circuit, is calculated by the model.

Experimental validation of the model was conducted on an engine head. The model correctly predicted measurements on the valve train.

As the engine head was fed by oil which could be mixed with air, parameters influencing the aeration in the HLA could be studied.