Modeling for optimization of circular flat pad aerostatic bearing with a single central orifice-type restrictor based on CFD simulation

For a circular flat pad aerostatic bearing with a single orifice-type restrictor, flow field in the air film is numerically investigated. The formation process of sonic region and shock waves is studied and formation mechanism of the vortex is revealed. Based on flow analysis, the maximum Mach number is taken as the benchmark of bearing dynamic stability and used as a constraint in the optimization modeling, for which the rationality is verified through transient flow calculations. The mathematical model for optimization considering both stiffness and dynamic stability is established, and several cases of optimization are performed under different given loads. The results are compared and benefits of the design optimization are demonstrated.