Thermal Analysis on Thrust Pad Bearing with Non-Newtonian Lubricant

Abstract

Hydrodynamic pad thrust bearings are widely used, due to their low friction, good load carrying capacity and high damping characteristics, in high speed rotating machines, such as pumps, compressors, turbines, turbo generators. However, the need for high load bearing capabilities and compactness of the thrust pad bearings has attracted the attention of engineers. The design of such thrust pad bearings involves selection of bearing materials, lubricants and operating conditions. As the performance of lubricants plays a vital role in the life cycle of bearings, thus the present work examines the thermophysical properties of non-Newtonian surrogate lubricants. The lubricant properties at different temperatures were extracted from NIST- Supertrapp ® and a correlation is developed which is further used in the computational analysis of thrust pad bearing. A steady state thermal analysis is done on the thrust pad bearings which are modeled and meshed in ANSYS ® 14.5. It was observed that the temperature variation on the outer surface to be varying linearly whereas a non-linear variation has been identified at inner surface of a pad in a thrust pad bearing initiating thermal stresses. Moreover, these thermal stresses may contribute finally to the reduction in performance with respect to wearing of pads. The present work also focuses on temperature dependent thermophysical properties on the temperature distribution of thrust pad bearings.