Used in several industrial fields to create innovative designs, topology optimization is a method to design a structure characterized by maximum stiffness properties and reduced weights. By integrating topology optimization with additive layer manufacturing and, at the same time, by using innovative materials such as lattice structures, it is possible to realize complex three-dimensional geometries unthinkable using traditional subtractive techniques. Surprisingly, the extraordinary potential of topology optimization method (especially when coupled with additive manufacturing and lattice structures) has not yet been extensively developed to study rotating machines. Based on the above considerations, the applicability of topology optimization, additive manufacturing, and lattice structures to the fields of turbomachinery and rotordynamics is here explored. Such techniques are applied to a turbine disk to optimize its performance in terms of resonance and mass reduction. The obtained results are quite encouraging since this approach allows improving existing turbomachinery components’ performance when compared with traditional one.

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.

The current trend in turbomachinery is pushing forward more and more efficient machines, increasing speeds, reducing components mass and improving their vibrational behaviour. Structural topology optimization is a challenging and promising approach to satisfy all these demands, with a very remarkable economic impact. This approach enables the creation of structures characterized by complex three-dimensional geometries, which are usually difficult or impossible to be produced using traditional manufacturing processes. However, thanks to innovative technologies, as new additive manufacturing techniques, it is now possible to effectively exploit topology optimization to develop innovative components. The aim of this work is to demonstrate the applicability of structural topology optimization techniques in turbomachinery, to improve the dynamic performances and vibrational behaviour of critical components. A 3D mock-up blade geometry based on T106 profile has been designed to reproduce a typical rotor blade in design conditions. The blade has been mounted on a rough disk model, to obtain a rotor blisk in order to ensure a wide design space for the optimization. The optimization has been carried out by applying mean and fluctuating loads coming from a 3D unsteady computation of 1.5stage (stator-rotor-stator) together with the centrifugal stresses. The unsteady loads acting on the rotor skin are due to the wake of the upstream stator and the potential field generated by the downstream stator. A new concept design for the blisk has been developed and the optimized geometry has been compared to the original one to highlight the improvements in terms of mass reduction and improved dynamic behaviour. This paper will confirm the suitability of this approach to turbomachinery components and a prototype of optimized geometry will be ready to be manufactured through innovative additive manufacturing techniques for high resistance alloys.

Topology optimization is an innovative strategy applied in the turbomachinery field with the aim of substantially improving the performances of turbomachinery components in terms of weights, stress levels and rotation speed, with a very remarkable economic impact. Being very flexible, topology optimization allows to manage the structures topology, significantly improving material distribution within a given design space for a given set of loads and boundary conditions. In this paper, the authors, in cooperation with General Electric Nuovo Pignone, develop a new concept design of a turbine disk and the optimized component is compared to the benchmark, in order to verify the achieved improvements. Special attention is paid to the use of innovative materials with lattice structures, characterized by complex three-dimensional geometries. Thanks to advanced technologies, as additive manufacturing, it is now possible to effectively exploit topology optimization to develop new components featured by complex structures. The developed prototypes will be manufactured and tested in the near future together with the industrial partners.

Structural topology optimization is an innovative approach in turbomachinery to satisfy the increasing demand for higher rotational speeds, light components and optimized natural frequencies, with a remarkable economic impact. Although this approach has never been extensively applied before to rotating machines, it is very promising for the mechanical optimization of rotor and stator components. This approach enables the creation of complex three-dimensional geometries, which are usually difficult or impossible to be built using traditional manufacturing methods. Thanks to innovative technologies and to the use of innovative materials, it is now possible to effectively exploit topology optimization. It allows to change the topology of the structures, significantly improving material distribution within a given design space for a given set of boundary conditions and loads. In this work, the authors have deeply investigated the applicability of topology optimization to the fields of turbomachinery and rotordynamics.