Influence of temperature on nonlinear dynamic characteristics of spiral-grooved gas-lubricated thrust bearing-rotor systems for microengine

The operating temperature of the gas thrust bearings for microengine is up to 1300–1700 K. The influence of temperature on both the gas viscosity and the rarefaction is considered to study the characteristics of the bearing-rotor systems. The molecular gas-film lubrication equation, discretized by employing the finite volume method, is systematically coupled with the kinetic equations and solved simultaneously. The results show that the temperature range can be divided into two regions: the viscosity effect domain region and the rarefaction effects domain region. The system exhibits the weakest stability when operating in the junction zone of the two regions.