An experimental and theoretical analysis of a foil-air bearing rotor system

Abstract

Although there is considerable research on the experimental testing of foil-air bearing (FAB) rotor systems, only a small fraction has been correlated with simulations from a full nonlinear model that links the rotor, air film and foil domains, due to modelling complexity and computational burden. An approach for the simultaneous solution of the three domains as a coupled dynamical system, introduced by the first author and adopted by independent researchers, has recently demonstrated its capability to address this problem. This paper uses this approach, with further developments, in an experimental and theoretical study of a FAB-rotor test rig. The test rig is described in detail, including issues with its commissioning.The theoretical analysis uses a recently introduced modal-based bump foil model that accounts for interaction between the bumps and their inertia. The imposition of pressure constraints on the air film is found to delay the predicted onset of instability speed. The results lend experimental validation to a recent theoretically-based claim that the Gümbel condition may not be appropriate for a practical singlepad FAB. The satisfactory prediction of the salient features of the measured nonlinear behavior shows that the air film is indeed highly influential on the response, in contrast to an earlier finding.

Dynamic Performances of Foil Bearing Supporting a Jeffcot Flexible Rotor System Using FEM

“…Among the technologies used successfully, one of them stands out with particularly interesting results and simple modeling: the technology of MITI-type stacking bearings [13]. Numerous numerical and experimental studies are interested in the static and dynamic characteristics of this type of bearings [4][5][6][7][8]14]. These papers focused on two areas:…”

“…One of the objectives was to validate their thermomechanical behavior at high temperatures [1,2]. Currently, the fields of application are more extensive but still concern the guidance of shafts rotating at very high speed, withstanding moderate loads and subjected to sometimes severe thermal stresses [3][4][5][6][7][8]. Some of them [3,5,9] consider the coupling between the bearing and the rotor with deformation of the sheets and friction between the sheets and the support using complex and numerically time-consuming approaches.…”

The influences of bump foil structure parameters on the static and dynamic characteristics of bump-type gas foil bearings

“…1,2 Breakthroughs in materials and manufacturing technology have intensified research into its applicability to an ever increasing range of turbomachinery. 3 There are different types of gas foil bearings, among which the bump-type is the most widely used one. 4 Bump-type gas foil bearing is mainly composed of a housing, a bump foil and a top foil, among which the bump foil is the core component.…”

Interference Torque of a Gas-Dynamic Bearing Gyroscope Subject to a Uniform Change of the Specific Force and the Carrier Angular Velocity

“…Chen [11] applied the Q-Z decomposition method to study the vibration of the stepped shaft supported by gas bearings, dividing the stepped shaft into wheel disc and shaft segment. Bonello et al [12][13][14] solved the Reynolds equation in the frequency domain, which is applied in the simulation of gas-dynamic foil bearing and rotor dynamics modeling of aero engines. Kim [15] solved the trajectory of the rotor with mass eccentricity and analyzed the condition for stability with the trajectory.…”