The effect of permeability distribution on the numerical analysis of aerostatic ceramic porous bearings

• Published in: Lubrication science Vol. 25; no. 2; pp. 185 - 194
• Main Authors: Nicoletti, Rodrigo, de Moraes Purquerio, Benedito, de Castro Silveira, Zilda
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-03-2013; Wiley Subscription Services, Inc
• Subjects: aerostatic bearing; Aerostatics; Bearings; Ceramics; Dynamics; Loads (forces); material permeability; Mathematical models; Monte Carlo simulation; Permeability; porous ceramic; Reynolds equation
• ISSN: 0954-0075; 1557-6833
• DOI: 10.1002/ls.1184

ABSTRACT
This work presents a numerical study on the effect of permeability on the static characteristics of aerostatic ceramic porous bearings. This study is important in bearing design because of the inherent permeability variation of the porous ceramic samples induced by manufacturing and sintering processes. The mathematical modelling of these bearings is based on the modified Reynolds equation, which depends on the pressure‐flow assumption (Darcy or Forchheimer) and on the static and dynamic permeability coefficients of the porous matrix. In this work, the modified Reynolds equation is numerically solved considering the variations of permeability values, whose distribution was obtained from experimental tests of the ceramic samples. Monte Carlo method is used to introduce variability in the solutions. One focuses on the effects of such variation on the results of predicted bearing loading capacity. Results show that optimum regions of the bearing load capacity do not vary significantly due to static and dynamic permeability variations. Copyright © 2012 John Wiley & Sons, Ltd.