Static and Modal Topology Optimization of Turbomachinery Components

Abstract

The need to be more and more competitive is pushing the complexity of aerodynamic and mechanical design of rotating machines at very high levels. New concepts are required to improve the current machine performances from many points of view: aerodynamics, mechanics, rotordynamics, and manufacturing. Topology optimization is one of the most promising new approaches in the turbomachinery field for mechanical optimization of rotoric and statoric components. It can be a very effective enabler to individuate new paths and strategies, and to go beyond techniques already consolidated in turbomachinery design, such as parametric and shape optimizations. Topology optimization methods improve material distribution within a given design space (for a given set of boundary conditions and loads) to allow the resulting layout to meet a prescribed set of performance targets. Topology optimization allows also to change the topology of the structures (e.g., when a shape splits into two parts or develops holes). This methodology has been applied to a turbine component to reduce the static stress level and the weight of the part and, at the same time, to tune natural frequencies. Thus, the interest of this work is to investigate both static and dynamic/modal aspects of the structural optimization. These objectives can be applied alone or in combination, performing a single analysis or a multiple analysis optimization. It has been possible to improve existing components and to design new concepts with higher performances compared to the traditional ones. This approach could be also applied to other generic components. The research paper has been developed in collaboration with Nuovo Pignone General Electric S.p.A. that has provided all the technical documentation. The developed geometries of the prototypes will be manufactured in the near future with the help of an industrial partner.