FULL-PARAMETRIC DESIGN SYSTEM TO IMPROVE THE STAGE EFFICIENCY OF A HIGH-FIDELITY HP TURBINE CONFIGURATION

摘要

This paper presents the application of an in-house automatic design system to the aerodynamic optimisation of one HP turbine stage. The main objectives of this study are: point out the importance of parametric geometry modelling and meshing for automatic design optimisation; move a step forward towards the exploitation of novel numerical tools to improve modern turbine performance with high-fidelity geometry configurations. In the present work, the system has been applied to the non-axisymmetric hub endwall optimisation of a research Rolls-Royce design HPT stage. The following main issues have been taken into account: high-fidelity CFD by means of multirow 3D simulations; parametric modelling and rapid meshing of real geometry features; modelling of film cooling flows.It is demonstrated that the integration of parametric models of secondary geometrical features within the mesh generator is a key issue in order to develop an effective and fully automated design procedure. It is shown that some of the benefits achieved optimising a simplified model of the stage are lost when applying the high-fidelity geometry configuration. A significant reduction of secondary flows and a corresponding increase of stage efficiency are achieved when taking into account the main real geometry features directly into the optimisation, even if at the cost of higher computational requirements.