MAGFLY The main focus of the MAGFLY project is the development of a technology for Smart Aero-Engines based on the use of Active Magnetic Bearings (AMBs). Future aircraft gas turbine engines are expected to provide better cycle performance, increased reliability and reduced weight in order to minimise both fuel consumption and emissions.

There is a drive towards greater efficiency with the 'More Electric Aircraft' and 'More Electric Engines’ and one of the ideas in this direction is to substitute the current mechanical bearing system by Active Magnetic Bearings (AMBs).

Imperial is the work package leader for Whole System Modelling, the aim of which is to develop a set of validated dynamic analysis modelling tools for the major components of a rotor system supported on AMBs. Individual components of a test rig have been modelled using ANSYS and validated viaMagfly 1 experiments. These components are then coupled with nonlinear components, e.g. the load-sharing bearings and AMBs. The technical challenge here is to reduce the calculation time of a large linear model with localised nonlinear elements.

Harmonic balance method is proposed to calculate steady state responses, which can significantly shorten the processing time comparing to the usual ime-marching method. The engine system in this particular case study is separated into two linear components (shaft and rotor), which are connected via a nonlinear interface. Eigen-solutions of the linear components are obtained from prior individual component modelling. The maximum displacements at the interested DOFs are calculated as a function of frequency. Substantial time saving was achieved.