Integrated Aero-Structural Optimization of a New Family of Transonic Centrifugal Compressor Impellers

Modern centrifugal compressor impellers are facing new challenges in support of the net-zero emissions target set by the Paris Agreement for 2050. In the evolving energy transition scenario, these machines must deliver higher efficiency and higher pressure ratios while at the same time reducing the carbon footprint. As a result, they are required to reach increasingly higher rotational speeds, which in turn implies higher stresses on the mechanical side. Thus, the structural design and optimization of impeller blade and dressing are crucial.

In order to meet technical targets and comply with time to market, it is crucial to adopt a design approach that seamlessly integrates both aerodynamic and structural requirements. This study proposes a multidisciplinary optimization framework for impeller design, leveraging Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) to evaluate and balance performance trade-offs between thermodynamic performance and mechanical integrity.

The impact of the main geometrical features was assessed through a parametric study. Moreover, feature importance techniques were used to achieve a smooth design for a new family of transonic impellers.

The strength of the proposed methodology lies in the robustness of the entire optimization process, which begins with geometric parameterization and extends to the automated generation of the solid model and the computational meshes for both solid and fluid domains.

The optimized designs exhibit higher admissible maximum continuous speeds (MCS) and maintain aerodynamic performance, offering a promising pathway for lightweight, high-efficiency turbomachinery components.