Optimisation methodologies applied to the design of a gas turbine cooling system

Daniele Coutandin (AVIO), Simone Taddei (Università degli Studi di Firenze), Massimo Galbiati, Francesco Pinto (Universita’ degli Studi di Trieste)

Design optimization techniques are a new frontier in engineering planning. Usually designers use “cut and try” methods in developing their projects, taking advantage of their Company’s Databases and internal know-how. Optimization algorithms can join this system and give a relevant improvement to the development time and design quality. In its R&D department , AVIO Group has began some projects in order to test the capabilities of  modeFRONTIER®, when coupled with its own software and methodologies and applied to turbo machinery problems. In this paper we illustrate some results obtained applying this methodologies to the aero-thermal field, and, in particular, to the turbine blade cooling design. The cooling systems of turbine blades use a percentage of the compressed air that cannot so be used in the main engine thermodynamic cycle. The reduction of this percentage, without decreasing the cooling effectiveness is one of the most important tasks in blade design. In fact, this reduction would grow up the whole engine performances. We show the results obtained applying a genetic Algorithm to an impingement cooling system acting on a simple test geometry. Particularly, a part of this work is focused on the choice of a variable set that allows to reduce the number of degree of freedom, with the minimal loss of flexibility. This will be useful when dealing with non-simple, three dimensional and high computational costing problems.