Numerical studies on aerostatic journal bearings for cryogenic turboexpanders

The reported study uses a model for evaluating both static and dynamic stiffness. It has been shown in the article that the dynamic component of the stiffness contributes mostly to the cross coupled component, which in turn contributes to the rotor instabilities. Different bearing configurations are proposed and studied for reduction of the cross coupled stiffness component. A numerical aerostatic journal bearing solver which includes the effects of shaft angular velocity, is developed and validated by experimental studies. A comparative study among the various configurations along with bearing parameters is presented which can serve as a guide for design and further development of high speed aerostatic journal bearings