An Investigation Into Laminar-to-Turbulent Transition in Tilting-Pad Bearings

It has long been known that superlaminar flow occurs in lubrication fluid films above a critical speed. The consequence of the transition from laminar to superlaminar flow is an increase in power losses, with corresponding changes in heat generation and operating costs. While a formula exists to predict the onset of superlaminar flow for hydrodynamic journal bearings, there is no clear criterion for the transition in tilting-pad thrust bearings. The paper describes a detailed investigation, performed on a large-scale model of a single tilting-pad, to obtain fundamental information on the transition phenomenon. Based on this work a lower critical Reynolds number of laminar-to-turbulent transition is proposed.