Oil flow, cavitation and film reformation in journal bearings, including an interactive computer-aided design study

An interactive computer program for the design of steadily
loaded fluid film, hydrodynamic journal bearings based on the procedure
of E S D U Item No. 66023 (1966) is presented. The program was developed
in two forms, a graphics and a non-graphics version. The computer
program procedure enabled a detailed study of the effect of changes
in the parameters on the bearing performance, which in turn permitted
the design of an optimized bearing.
A theoretical and experimental study of the influence of film
reformation on the performance of hydrodynamic journal bearings, and
the side flow rate in particular, is also presented. A numerical
analysis technique based on a cavitation algorithm proposed by H.G.
Elrod was developed. This technique was capable of an automatic
d etermination of the boundaries of the cavitation region and included
a consideration of the lubricant inlet conditions (groove geometry and
supply pressure). Theoretical data for journal bearings with a single
axial groove located at the position of maximum film thickness is
presented for a wide range of the values of the bearing design and
o perating parameters.
An apparatus was designed and commissioned to study the lubricant
flow rate in journal bearings. Tests were performed wi t h three glass
bushes of width-to-diameter ratio of unity at variable values of
eccentricity ratio and lubricant supply pressure. The agreement achieved
between theory and experiment for dimensionless side flow rate was
excellent. For the location of the film reformation boundary, the
correlation between theoretical predictions and experimental measurements
was satisfactory, except at low values of eccentricity ratio and
dimensionless supply pressure.
A study of the correlation between the predictions of dimensionless
load capacity, attitude angle and dimensionless side flow rate obtained
from ESDU Item No. 66023 (.1966) and those of the new bearing analysis
reported in the thesis is presented. Good agreement was observed for
the predictions of side flow rate.