Investigation of journal orbit and flow pattern in a dynamically loaded journal bearing

Abstract

A hydrodynamic journal bearing has been investigated using both the traditional two-dimensional (2D) Reynolds equation, and the full solution being the three-dimensional (3D) Navier-Stokes equations. The two approaches are compared by performing an investigation of two inlet groove designs: the axial and the circumferential groove, respectively, on a bearing with length-to-diameter ratio of 0.5 exposed to a sinusoidal load pattern. Pressure distributions, journal orbits and frictional losses are compared. The modelling of grooves by pressure boundary conditions versus geometric conditions is examined. It is investigated if the presence of a groove increases frictional losses and the increase relates to groove dimensions. Furthermore, the influence of the groove design on the flow field is studied using the 3D solution.

Study on Lubrication Efficiency and Friction Power Loss of Engine Based on a Hybrid Hydrodynamic Model

“…Studies show that the oil film in the CB is usually divided into the liquid zone and cavitation zone, in which the oil film often ruptures [13]. Therefore, the cavitation region is often challenging to calculate effectively due to the negative pressure caused by gas dissolution and cavitation effects [18][19]. In this study, instead of ignoring negative pressures in the cavitation zone, only pressures below the saturation pressure, ps is varied to reach the effective pressure pe [15].…”

Combined Influence of Noncondensable Gas Mass Fraction and Mathematical Model on Cavitation Performance of Bearing

“…Guo et al [12] established a three-dimensional gas-liquid mixed-phase CFD model, and analyzed the effect of noncondensing gas on the pressure field and phase field using a fully cavitated model. Christian et al [13] studied the pressure, the axial track, and the friction loss of the axial and circumferential grooves journal bearing, based on the three-dimensional N-S equation. Ji and Cheng et al [14,15] studied numerically the cavitating flow around a NACA66 hydrofoil, and carried out numerical simulations of a tip leakage cavitating flow of a straight NACA009 hydrofoil.…”

Effect of perturbation amplitudes on water film stiffness coefficients of water-lubricated plain journal bearings based on CFD–FSI methods

“…High-precision experimental work in the field of rotor dynamics was required; 21 new effective non-linear bearing models 22–25 and additional studies to consider the influence of thermal and elastic distortion, grooving arrangements, misalignment, cavitation and film reformation were also needed. 26–30…”

“…Highprecision experimental work in the field of rotor dynamics was required; 21 new effective non-linear bearing models [22][23][24][25] and additional studies to consider the influence of thermal and elastic distortion, grooving arrangements, misalignment, cavitation and film reformation were also needed. [26][27][28][29][30] It had been proved experimentally that the negative pressure existed in the film divergence region. 29,30 In order to suggest a different and reliable description of the dynamic state of a journal bearing, Kicin´ski 31 proposed a theoretical model of the cavitated zone and an equation allows one to determine the boundaries of the cavitated lubricating film in his study.…”