Prediction of Temperature Fade in the Cavitation Region of Two-Lobe Journal Bearings

Abstract

Experimental evidence has shown that there often exists a considerable drop in bush temperature (the so-called temperature fade) in the cavitation region of journal bearings. This is contrary to the predictions of the conventional thermohydrodynamic analyses which give more or less rising temperatures. In order to bring theory into accord with experiment, an elemental heat-balance method was established by the authors to predict the temperatures in the cavitation region of two-lobe journal bearings. In this approach, the effect of oil back-flow from feed grooves was included on the basis of the separation cavitation model. Comparison between theory and experiment for a two-axial-groove circular bearing and an elliptical bearing has indicated that the present method is very effective in predicting the temperature fade. The analysis for the prediction of temperatures in the exit cavitation region is in principle applicable to multi-lobe journal bearing situations.