Stability and thermohydrodynamic investigations of wave journal bearings

The purpose of this thesis is to investigate the dynamic stability and the thermohydrodynamic behavior of a wave journal bearing. A thorough description as well as the geometrical parameters and the properties of the wave bearing are presented in the beginning of the thesis.;The influence of the wave bearing parameters on the pressure distribution inside the fluid film is analyzed. For this purpose the Reynolds equation is integrated by using two different finite difference schemes. The methods predict very close results.;The influence of the wave amplitude ratio and of the supply pressure on the dynamic behavior of a wave bearing is also studied. The stability threshold is predicted by using two different approaches: a critical mass approach and a transient approach. The transient approach predicts the behavior of the journal center after the fractional frequency whirl appears. Turbulence and temperature effects are included in the computations. The computational codes are validated by comparing the numerical results predicted by the two methods to each other and to experimental data.;The thermohydrodynamic behavior of a wave bearing is investigated by simultaneously solving the Reynolds and energy equations in the lubricant film and the conduction equations for the sleeve and the shaft. Two types of investigations are performed in this case: (1) the applied load is constant and the rotational speed is variable and (2) the rotational speed is constant and the applied load is variable. The code is validated by comparing the numerical results to experimental data.