Coupled Aero-Thermo-Mechanical Simulation for a Turbine Disc Through a Full Transient Cycle

Use of computational fluid dynamics (CFD) to model the complex, 3D disc cavity flow and heat transfer in conjunction with an industrial finite element analysis (FEA) of turbine disc thermo-mechanical response during a full transient cycle is demonstrated. The FEA and CFD solutions were coupled using a previously proposed efficient coupling procedure. This iterates between FEA and CFD calculations at each time step of the transient solution to ensure consistency of temperature and heat flux on the appropriate component surfaces. The FEA model is a 2D representation of high pressure (HP) and intermediate pressure (IP) turbine discs with surrounding structures. The front IP disc cavity flow is calculated using 45° sector CFD models with up to 2.8 million mesh cells. Three CFD models were initially defined for idle, maximum take-off (MTO) and cruise conditions, and these are updated by the automatic coupling procedure through the 13000 seconds full transient cycle from standstill, to idle, maximum take-off, and cruise conditions. The obtained disc temperatures and displacements are compared with an earlier standalone FEA model which used established methods for convective heat transfer modelling. It was demonstrated that the coupling could be completed using a computer cluster with 60 cores, within about two weeks. This turn around time is considered fast enough to meet design phase requirements and in validation it also compares favorably to that required to hand-match an FEA model to engine test data, which is typically several months.