In this thesis, numerical analysis is conducted to investigate the performance of hydro-dynamic gas foil journal bearings. The behavior of gas is described by the Reynolds equation. It is assumed that the foil deformation is proportional to the pressure of gas film. The equations about the pressure in the gas film and gas film thickness are solved simultaneously. A perturbation method is used to obtain the linearized dynamic coefficients. A finite difference method is used for this analysis.
Load capacity, steady-state journal position, stiffness and damping coefficients are calculated. The effects of foil compliance distribution are discussed. As foil compliance is increased, load capacity is increased while dynamic coefficients are decreased. The foil compliance at the position where maximum pressure is developed has significant effects on the performance of the bearings.
