Analytic-CFD Combined Method for Analysis of Mechanical Properties of Externally Pressurized Gas Journal Bearing

For mechanical performances analysis of externally pressurized gas journal bearings, the engineering analytic method is convenient to use but the solution precision is poor due to the use of several hypotheses. The computational fluid dynamics(CFD) method possesses a high precision but it is inconvenient to apply due to the difficulty of numerical modeling, large scale of the numerical model and poor calculation convergence. To overcome these demerits and use advantages of both methods, analytic-CFD combined method is proposed for the analysis of mechanical performances of externally pressurized gas journal bearings. Through application of the combined method, load carrying capacity and stiffness of the bearing can be achieved under the consideration of detailed flow field characteristics of the air film. Calculations of mechanical performances of an externally pressurized gas journal bearing are performed by using the traditional engineering analytic method and the present combined method, respectively. Meanwhile, the related experimental measurement is also carried out. Based on the calculations, the bearing load carrying capacity and stiffness are achieved, and the comparison between calculated results and experiment results shows that the analytic-CFD combined method possesses a higher precision than the traditional engineering analytic method.