A new gaseous cavitation model in a tilting-pad journal bearing.

Abstract

With the higher rotational speeds and loads in bearings, the gaseous cavitation becomes more and cannot be ignorable in the bearing designs. However, there is no enough research in non-equilibrium gaseous cavitation model. This paper builds a new gaseous cavitation model based on the Bunsen solubility and bubble dynamics. The equilibrium pressure is calculated by the Bunsen solubility based on the local pressure and its pressure difference with the local pressure decides the cavitation mass transfer rate in this new model for gaseous cavitation. A titling-pad journal bearing at 3000 rpm and under 299 kN load is chosen as the research object with this new model and an original equilibrium model applied. As for the minimum film thickness and bearing force balance, this new model performs in better accordance with the experiment than the equilibrium model. According to the multiphase distributions in the bearing film, the gaseous cavitation rate in this new model can simulate the non-equilibrium processes of dissolution and cavitation under the high rotational speed, which is close to the physical gaseous cavitation process. This new model is developed and applied successfully in tilting-pad journal bearings for simulating the non-equilibrium gaseous cavitation.