- Knight, Josiah D. and Ghadimi, Parviz, Effects of modified effective length models of the rupture zone on the analysis of a fluid journal bearing,
Tribology Transactions, vol. 35 no. 1
pp. 29 - 36 .
(last updated on 2007/04/06)
Two versions of a model for the thermal behavior of the lubricant film in the cavitation region of a journal bearing are presented and incorporated into a solution algorithm for the operating characteristics of an axially grooved bearing. The model is based on an approximation of the flow as two parts: Couette-like streamers plus uniform velocity portions adhered to the journal. One version, the cavity height (CH) model, results from assuming a constant ratio between the cavity height and the local gap height. The other, the fluid height (FH) model, results from assuming a constant thickness of the adhered fluid layer. An approximate energy equation is derived for the rupture zone and is applied to the calculation of the bearing wall temperature. Parametric studies of the effects of the choice of cavity dimensions indicate that for appropriate choices the agreement between theory and published experiment is significantly better for the new methods. Agreement is lightly better for the FH model that for the CH model, and because of physical arguments the FH model is preferred. Results for the cases examined are consistent with an adhered layer having a thickness approximately 40 percent of the gap height at the rupture boundary.
Bearings--Cavitation;Lubricants--Films;Lubrication--Thermal Effects;Thermodynamics--Mathematical Models;Mathematical Techniques--Numerical Methods;