Topology Optimization applied to the Impeller-Diffuser Design of Centrifugal Compressors considering 3D Domains

Resumo

Efficient carbon dioxide compression is crucial to the feasibility of certain carbon capture, utilization, and storage (CCUS) systems, which are indispensable tools in the global effort to mitigate greenhouse gas emissions (IEA, 2021). Given that compressors are responsible for the majority of energy consumption in some CCUS processes (Allahyarzadeh-Bidgoli et al., 2021), discovering innovative solutions that could enhance the performance of this devices is therefore a relevant engineering challenge. This study applies topology optimization to the impeller-diffuser configuration in centrifugal compressors, aiming to explore the impact of considering three-dimensional (3D) design domains on the resulting topologies and performance metrics. The optimization problem uses a multi-objective function to minimize energy dissipation while maximizing impeller pressure head, diffuser pressure recovery, and total energy transfer. Design variables are defined as a pseudo-density field that controls local porous media resistance, with volume constraints applied to both rotating and stationary zones and binary material distribution enforced via the TOBS algorithm. The fluid flow is governed by the Navier–Stokes equations with rotational effects modeled using the Multiple Reference Frame (MRF) approach, and turbulence is treated with the Wray-Agarwal model. Sensitivities are computed using a high-level discrete adjoint method combining OpenFOAM and FEniCS/dolfin-adjoint through the FEniCS-TopOpt-Foam library. Accordingly, results are obtained under laminar and turbulent incompressible steady-state flows in both two-dimensional (2D) and three-dimensional (3D) design domains. Numerical results are included for comparing laminar and turbulent flow regimes, comparing 2D and 3D domain configurations, and varying different weight combinations in the multi-objective function. These results highlight how turbulence modeling and accounting for 3D effects leads to significantly different optimized topologies, offering valuable insights for the design of impeller-diffuser configuration in high-performance centrifugal compressors.
References:
Allahyarzadeh-Bidgoli, A. et al. (2021). “Thermodynamic analysis and optimization of a multi-stage compressionsystem for CO2 injection unit: NSGA-II and gradient-based methods”.
International Energy Agency (2021). Net Zero by 2050: A Roadmap for the Global Energy Sector.