A two-phase flow approach to cavitation modelling in journal bearings

Abstract

Cavitation has been extensively treated in numerical models for lubrication using boundary conditions in the pressure equation, and several criteria are available. However, an inappropriate choice can lead to imprecise results, thus having serious implications for performance prediction. This work proposes the numerical solution for lubrication analysing the changes suffered by the lubricant along a journal bearing, considering the release of gas from the liquid and the existence of a two-phase flow. Results obtained are compared with those using the Reynolds, or Swift-Steiber, boundary condition. The influence of fluid properties on the main parameters of bearing operation is also discussed.

An Arbitrary Lagrangian–Eulerian Formulation for Modelling Cavitation in the Elastohydrodynamic Lubrication of Line Contacts

“…Kumar and Booker [30] derived a solution for two-phase flow in journal bearings which modifies the Elrod model [14] and is a widely cited cavitation algorithm. Grando et al [31] developed a two-phase model for journal bearings by considering the interaction between liquid and gas properties and phase dissolution. Bayada and Chupin [32], Bruyere et al [33], and van Odyck and Venner [34] have all developed models investigating two-phase flows in lubricated contacts.…”

Dynamics of gas bubble growth in oil-refrigerant mixtures under isothermal depressurization

“…Although the first studies concerning the lubrication of the compressor sliding parts neglected the presence of refrigerant dissolved in the oil Rigola et al, 2003;Cho and Moon, 2005;Couto, 2006), they undoubtedly have set the foundations for the more recent class of lubrication models that considered the effect of a lubricant mixture composed of refrigerant and oil. Among these studies, Grando et al (2006b) proposed simplified lubrication models for journal bearings considering the interaction between the oil and the refrigerant and the existence of a gas/liquid two-phase flow in the lubricant film. Grando et al Their results indicated an increase of friction losses followed by a reduction in load capacity due to the presence of gaseous refrigerant dispersed in the lubricant film.…”

Mathematical Modeling of the Ester Oil-Refrigerant R134a Mixture Two-Phase Flow with Foam Formation Through a Small Diameter Tube

“…Some researchers have focused on the lubricating characteristics of the mixture: Jonsson (1999), Chul Na, Chun and Han (1997), Grando, Priest and Prata (2006). Other researchers have studied the transient processes of absorption and separation (outgassing) of refrigerant in oil, which is useful, for example, to estimate the concentration of refrigerant in the oil stored inside the compressor in the start-up condition: Silva (2004) and Fukuta et al (2005).…”