Non-Linear Dynamics, Instability and Chaos of Two Spool Aero Gas Turbine Rotor System

The study provides an insight into the non-linear dynamic analysis of a two spool aero gas turbine rotor system. A nonlinear finite element model of the twin spool system is developed using Timoshenko beam element, considering the elastic deflections of the bearings and resulting nonlinear Hertz contact forces, coupled with the radial clearances present in the bearing. A brief study on the instability is performed on a modified two spool system with non-linearity present only at the inter-shaft bearing. The instability study was performed using shooting technique coupled with fixed point algorithm. An overview on chaotic dynamics of the system is also done on the same system using Wolf algorithm. Effect of bearing clearances, rotor speed and unbalance on the response, instability and chaos has also been discussed.