Experimental pressure field in radial journal bearings and comparison with analytical and numerical results

Experimental temperature and pressure profiles are reported for hydrodynamic Journal Bearings (JBs) operating under various load and speed conditions. Three aspect ratios, L/D (length over diameter), are considered, 1/4, 1/2 and 1. The behavior of this tribological system is governed by two dimensionless numbers, L/D and eta (eccentricity over radial clearance). In a previous work, we presented a regular perturbation method that extended the Ocvirk solution (known as Infinitely Short Journal Bearing, ISJB) and successfully described isothermal JBs up to L/D and eta of about 3/4 (Vignolo et al. in Tribol Int 44:1089-1099, 2011). Currently, we compare this methodology and numerical results with experimental data obtained in our test rig machine by varying load, speed and L/D. The results show that oil temperature is mainly affected by rotor speed, while load and aspect ratio have a minor effect within the range of conditions tested. Furthermore, very good agreement is observed between most of the pressure measurements and the predicted profiles at all aspect ratios. The similarity in both shape and maximum values is excellent at small L/D, while the values tend to be slightly underestimated as the Ocvirk number decreases and L/D increases.