Towards Structural Topology Optimization of Rotor Blisks

Author(s):  
Enrico Boccini ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Lorenzo Pinelli ◽  
Lorenzo Peruzzi ◽  
...  

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.

Author(s):  
Enrico Boccini ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Simone Corbò ◽  
Stefano Falomi ◽  
...  

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.


Author(s):  
Enrico Boccini ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Simone Corbò ◽  
Giuseppe Iurisci

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.


2021 ◽  
pp. 1-31
Author(s):  
Lorenzo Pinelli ◽  
Andrea Amedei ◽  
Enrico Meli ◽  
Federico Vanti ◽  
Benedetta Romani ◽  
...  

Abstract The need for high performances is pushing the complexity of mechanical design at very high levels, especially for turbomachinery components. Structural topology optimization methods together with additive manufacturing techniques for high resistant alloys are considered very promising tools, but their potentialities have not been deeply investigated yet for critical rotating components like new-generation turbine blades. This research work proposes a methodology for the design, the optimization and the additive manufacturing of extremely stressed turbomachinery components like turbine blade-rows. The presented procedure pays particular attention to important aspects of the problems as fluid-structure interactions and fatigue of materials, going beyond the standard structural optimization approaches found in the literature. The numerical procedure shows robustness and efficiency, making the proposed methodology a good tool for rapid design and prototyping, and for reducing the design costs and the time-to-market typical of these mechanical elements. The procedure has been applied to a low-pressure turbine rotor to improve the aeromechanical behavior while keeping the aerodynamic performance. From the original geometry, mode-shapes, forcing functions and aerodynamic damping have been numerically evaluated and are used as input data for the following topological optimization. Finally, the optimized geometry has been verified in order to confirm the improved aeromechanical design. After the structural topology optimization, the final geometries provided by the procedure have been then properly rendered to make them suitable for additive manufacturing. Some prototypes of the new optimized turbine blade have been manufactured to be tested in terms of fatigue.


2011 ◽  
Vol 267 ◽  
pp. 297-301
Author(s):  
Yong Wang ◽  
Guo Niu Zhu ◽  
Bo Yu Sun

The paper is concerned with topology optimization in the mechanical design process. The disadvantage of current process of mechanical design is discussed and a new design process based on structural topology optimization is presented. The design process with structural topology optimization in mechanical design is discussed by the example of the frame of a bender. Static analysis is made to the original model first according to the whole structure and working characteristic of the machine, the stress and deformation distribution are obtained and then topology optimization is carried out. On the basis of topology optimization, the layout of the initial design proposal is obtained and the weight of the frame is substantially reduced while the performance enhanced. The application of the method demonstrates that through innovative utilization of the topology optimization techniques, the conceptual proposals can be obtained and the overall mechanical design process can be improved substantially in a cost effective manner.


Author(s):  
Andrea Amedei ◽  
Enrico Meli ◽  
Andrea Rindi ◽  
Benedetta Romani ◽  
Lorenzo Pinelli ◽  
...  

Abstract The need for high performances is pushing the complexity of mechanical design at very high levels, especially for turbomachinery components. In this field, structural topology optimization methods together with additive manufacturing techniques for high resistant alloys are considered very promising tools, but their potentialities have not been deeply investigated yet for critical rotating components like new-generation turbine blades. In this framework, this research work proposes a methodology for the design, the optimization and the additive manufacturing of extremely stressed turbomachinery components like turbine blade-rows. The presented procedure pays particular attention to important aspects of the problems as fluid-structure interactions (forced response and flutter phenomena) and fatigue of materials, going beyond the standard structural optimization approaches found in the literature. The new design strategy enables a substantial reduction of the component mass, limiting the maximum stress and improving the vibrational behaviour of the system in terms of eigenfrequencies, modal shapes and fatigue life. Furthermore, the numerical procedure shows robustness and efficiency, making the proposed methodology a good tool for rapid design and prototyping, and for reducing the design costs and the time-to-market typical of this kind of mechanical elements. The procedure has been applied to a low-pressure turbine rotor to improve the aeromechanical behavior while keeping the aerodynamic performance. From the original geometry, mode-shapes, forcing functions (due to rotor/stator interactions) and aerodynamic damping have been numerically evaluated and are used as input data for the following topological optimization. Finally, the optimized geometry has been verified in order to confirm the improved aeromechanical design. After the structural topology optimization, the final geometries provided by the procedure have been then properly rendered to make them suitable for additive manufacturing. Some prototypes of the new optimized turbine blade have been manufactured from aluminum to be tested mechanically and in terms of fatigue.


2011 ◽  
Vol 464 ◽  
pp. 655-659
Author(s):  
Yong Wang ◽  
Guo Niu Zhu ◽  
Zheng Wei Zhu

Structural topology optimization has got a general acceptance in recent years in mechanical design due to its powerful technique for conceptual design. The shortcoming of current development process of mechanical design is discussed and a new approach with structural topology optimization is put forward. The application of the method demonstrates that through innovative utilization of the topology optimization techniques, a multitude of conceptual design proposals based on the design space and design targets can be obtained and then a CAD model with high quality which has a positive impact on the development process is also available.


2021 ◽  
Vol 64 (4) ◽  
pp. 2627-2652 ◽  
Author(s):  
Michele Marino ◽  
Ferdinando Auricchio ◽  
Alessandro Reali ◽  
Elisabetta Rocca ◽  
Ulisse Stefanelli

AbstractWe propose a variational principle combining a phase-field functional for structural topology optimization with a mixed (three-field) Hu–Washizu functional, then including directly in the formulation equilibrium, constitutive, and compatibility equations. The resulting mixed variational functional is then specialized to derive a classical topology optimization formulation (where the amount of material to be distributed is an a priori assigned quantity acting as a global constraint for the problem) as well as a novel topology optimization formulation (where the amount of material to be distributed is minimized, hence with no pre-imposed constraint for the problem). Both formulations are numerically solved by implementing a mixed finite element scheme, with the second approach avoiding the introduction of a global constraint, hence respecting the convenient local nature of the finite element discretization. Furthermore, within the proposed approach it is possible to obtain guidelines for settings proper values of phase-field-related simulation parameters and, thanks to the combined phase-field and Hu–Washizu rationale, a monolithic algorithm solution scheme can be easily adopted. An insightful and extensive numerical investigation results in a detailed convergence study and a discussion on the obtained final designs. The numerical results clearly highlight differences between the two formulations as well as advantages related to the monolithic solution strategy; numerical investigations address both two-dimensional and three-dimensional applications.


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