A STUDY OF TURBULENT LUBRICATED HYDROSTATIC/HYBRID MULTIRECESS 3 LOBE JOURNAL BEARINGS

Abstract

Bearing are used extensively in all rotating machinery in the industry to support load. Their performance plays an important role in chemical, petrochemical, automotive, power generation, aerospace, turbo machinery and process industries. Bearing are generally designed on the basis of empirical relations and design charts provided. Pioneering work in this field done by Rowe and his co-workers. Further, the machines are required to be operated under a very high speed. Therefore, the bearings are design on the basis of more accurate predicted design data. The performance of hydrostatic/hybrid journal bearing system get affected by number of factor such as type of restrictor, bearing shell flexibility and mode of operation of bearing, offset factoc etc. it also depend on the load arrangement and turbulence in journal bearings and wear. The phenomenon of turbulence in lubrication has attracted the attention of many researchers. The turbulence occurs in the bearings basically for two reasons; high speed operation, and the use of unconventional lubricants of low kinematics viscosity such as water, synthetic lubricants or liquid metals. The aim of the present work is to analyze the performance of a non circular hydrostatic/hybrid journal bearing system under combine effect of turbulence and wear. This in turn modifies the fluid film thickness profile and ultimately changes the bearing -performance. For computing the bearing performance characteristics, the Reynolds equation for the flow of lubricant in the clearance space with equation of flow through restrictor as a constraint has been solved using appropriate boundary conditions. The flow field solution domains has been discreatized using 4- noded isoparametric elements. The static and dynamic performance characteristics are presented for various effects and conclusions are drawn.