Influence of Inlet Conditions on the Thermohydrodynamic State of a Fully Circumferentially Grooved Journal Bearing

Abstract

A thermohydrodynamic (THD) analysis of a fully circumferentially grooved hydrodynamic bearing is presented. The pressure distribution is obtained using the short bearing approximation taking into account the viscosity variation in the radial and circumferential coordinates. The axial temperature variation is also included by an axial averaging technique, which incorporates the supply pressure and film entry temperature in the energy equation. It is found that the determination of the lubricant temperature at the entry to the film plays an important role in the overall temperature distribution in the bearing. A simplified approach for determining this temperature is presented. An extensive set of experimental results performed by Maki and Ezzat (1980, ASME J. Lubr. Technol., 102, pp. 8–14) is used for validation purposes. The results show that mixing in the inlet groove may cause the film entry temperature to be significantly different from the nominal supply temperature and hence have a significant influence on the bearing temperature.

The role of lubricant feeding conditions on the performance improvement and friction reduction of journal bearings

“…An analysis of the influence of oil inlet conditions on the THD performance of the fully circumferentially grooved journal bearings was performed by Keogh and Khonsari [20]. A simplified axial averaging technique was used, that enabled the groove pressure and the entry temperature to the lubricant film to be explicitly incorporated into the lubricant energy equation and highlighted that the mixing effect must be always taken into account.…”

A Method of Feeding Conditions Monitoring of Journal Bearing in Tandem Cold Mill

“…Heshmat and Pinkus 6 studied the mixing inlet October 2016 Vol 49 No 8 l Measurement and Control 257 temperatures in hydrodynamic bearings as a function of a range of operating conditions for both journal and thrust bearings. Keogh and Khonsari 7 introduced a thermohydrodynamic analysis and found that mixing in the inlet groove might cause a significant influence on film entry temperature. Ma and Taylor described an experimental apparatus.…”

THD Analysis of Journal Bearings: A Finite Element Algorithm for Groove Mixing Conditions

“…Several authors have proved that consistent determination of the film entry temperature plays an important role in realistically predicting the bearing temperature distribution. They have therefore provided various algorithms, depending on the groove and bearing type [1,2,3], in order to model the mixing of incoming supply oil with re-circulating oil in the feed grooves. However, a unified treatment of the groove-mixing energy balance independent of the particular geometry has not yet been devised.…”