Author(s)

M. Bäuml & J. Heinzl

Abstract

A new and very fast simulation method for the fluid-structure interaction of an axial bearing is presented. Innovative applications require level surfaces with an area of several hundred square meters where air bearings carry loads of more than 5 tons. The sliding speed is assumed to be low. The ground consists of several segments. When the bearing is crossing the gap between two assembled plates, a step with a height of 10 to 20µm appears due to elastic deformation of the segments. The resulting excitation leads to axial and tilt oscillation. This dynamical interaction between the air cushion, the step in the ground and the superposed oscillation of the rigid bearing is very complex but can be simulated with the new method. The presented simulation method was entirely developed in Visual Basic and allows visual control during computation. The simulation is based on the finite volume technique. The new simulation method basically shows the same characteristics as the measurement results. The simulation time compared to other simulation tools is very low. It is in the regime of seconds to calculate an air bearing with a diameter of 80mm crossing a step of 2µm in the level surface. This time advantage is achieved with a simple model for the dynamic motion of a rigid body combined with a finite volume simulation for the flow in the gap and an analytical description of the nozzles. Further adaptation will result in a simulation tool which allows design calculations for dynamically stimulated aerostatic bearings. Keywords: interaction of air with bearing support, finite volume simulation, aerostatic axial bearing, compressible fluid, rigid body motion.

Keywords

interaction of air with bearing support, finite volume simulation, aerostatic axial bearing, compressible fluid, rigid body motion.