Finite element analysis of a rotor system with squeeze film damper

Abstract

Consulta en la Biblioteca ETSI Industriales (8217)

[EN] In this master thesis the objective is to develop an accurate model of the shaft of a turboprop that is being design as part of the CESAR project. A beam element model was tested in ANSYS Mechanical, and it showed the di - culty of having a model that could predict accurately the behavior of the turboprop system. The problems were mainly due to the complex behavior of a squeeze lm damper mounted on the shaft in order to provide damping and making easy to cross the critical speeds. In order to model the SFD, the Reynolds equation is solved using the nite element method. The Reynolds equation gives us the pressure distribution of the oil lm inside the damper when it is squeezed between the stationary and the moving part. When we have the pressure distribution we could calculate the reaction forces and the mass ow. After developing a program that solves the equation using the nite element method, it was possible to calculate the sti ness and damping characteristics of the damper, using the equation that relate the forces appearing in a damper with the displace- ments and the velocities of it. Using the program that we have called reynfem , we have studied how the di er- ent characteristics of a damper a ect its behavior. For several lengths, speeds and viscosities the sti ness and damping coe cients present in the damper have been calculated. Then, the rotordynamic analysis of a beam model of the shaft of a turboprop is done using ANSYS Mechanical. We have studied how the sti ness and damping coe cients at the SFD a ect the displacement of the shaft.