threshold with high amplitude vibration one has to perform transient, non-linear analysis. It has been observed that in oil a lubricated journal bearing, there is about 30 to 40o F temperature difference around the circumference. As a result, there can be 30-50 % drop in lubricant viscosity, which can drastically change the characteristic of the system. To avoid catastrophic bearing failure, these effects much be taken into consideration at the design stage. A realistic approach to the problem is by including the thermal effects and performing the complete THD (Thermohydrodynamic) analysis of the rotor-bearing system.
A Rotor Dynamic test rig has been built to perform experimental research on thermal effects on oil whirl. The Rig is equipped with vibration and temperature transducers are capable of running at top speed of 10,000 rpm. Benly’s ADRE is used for data acquisition and analysis.

The objectives of this research are
1)To control oil whirl by varying the temperature of lubricant.
2)To come up with an analytical tool that can predict the non-linear oil whirl threshold. This information will be used for design purposes.