An integrated system for the aerodynamic design of compression systems-part II: Application

The complexity of modern gas turbine engines has led to the adoption of a modular design approach, in which a conceptual design phase fixes the values for a number of parameters and dimensions in order to facilitate the subdivision of the overall task into a number of simpler design problems. While making the overall problem more tractable, the introduction of these process-intrinsic constraints (such as flow areas and radii between adjacent stages) at a very early phase of the design process can limit the level of performance achievable, neglecting important regions of the design space and concealing important trade-offs between different modules or disciplines. While this approach has worked satisfactorily in the past, the continuous increase in components' efficiencies and performance makes further advances more difficult to achieve. Part I of this paper described the development of a system for the integrated design optimization of gas turbine engines: postponing the setting of the interface constraints to a point where more information is available facilitates better exploration of the available design space and better exploitation of the trade-offs between different disciplines and modules. In this second part of the paper, the proposed approach is applied to several test cases from the design of a three-spool gas turbine engine core compression system, demonstrating the risks associated with a modular design approach and the consistent gains achievable through the proposed integrated optimization approach.