Transferring Information from CFD to FE Thermal Analysis. Application to a cooling film.

Abstract

This Master’s Thesis was conducted at GKN Aerospace, Trollhättan. In this project different one way coupling procedures between computational fluid dynamics (CFD) and finite element analysis (FEA) has been evaluated. A method using 1D thermal loads for the structural simulations was compared a newly proposed method using 2D Thermal loads. Two inhouse codes BCgen2 and BCgen_2D_mapping from GKN Aerospace were used to supply thermal loads of one and two dimensions respectively. Conjugated CFD was used as reference in both case one and case two. As a first case a 2D boundary layer was simulated in ANSYS® Fluent® which demonstrated the importance of the choice of reference temperature. The results shows that the most appropriate temperature was the adiabatic wall temperature. The second case included a turbine cascade geometry in three dimensions modified to include a leak flow slot and a strut fillet radius. The use of thermal loads of two dimensions on the hub surface proved to result in superior temperature predictions compared to the 1D method. The methods were also applied to an existing turbine rear structure geometry. Details of the hot wake area as well as temperature difference in the hub region closest to the vane, resolved using 2D thermal loads, resulted in significant differences in the level of material stresses predicted compared to the ones given using 1D thermal loads.