Turbine Stator Well Geometry Benefits - Method Validation and Design Optimisation

This paper summarises the two part work carried out during project 7 of work package 3 of the EU funded research project AMEDEO. At first, the outcome of a practical application and extension of a numerical coupled FEA-CFD methodology is presented. Extensive use is made of FEA (solids) and CFD (fluid) modelling techniques to understand the thermo-mechanical behaviour of a turbine stator well cavity, due to the interaction of cooling air supply with the main annulus. In this investigation, two different geometries (baseline and a deflector plate design) with a specific amount of cooling air are modelled and the impact of the structural deflections on the heat transfer is investigated. The second part focuses on a CFD-based automated optimisation of a turbine stator well (TSW) geometry with an included stationary deflector plate. Experiments as well as numerical simulations have shown that due to the deflector plate the cooling flow is fed more directly into the disc boundary layer, allowing more effective use of less cooling air, leading to improved engine efficiency. Therefore, the deflector plate geometry is embedded in an automated optimisation loop to further reduce the amount of cooling air. The optimisation strategy concentrates on a flexible design parameterisation of the cavity geometry with deflector plate and its implementation in an automatic 3D meshing system. The parameterised geometry is optimised using a metamodel-assisted approach based on regressing Kriging in order to identify the optimum position and orientation of the deflector plate inside the cavity.