Topology optimization of turbulent rotating flows using Spalart-Allmaras model

The design of rotating fluid devices, such as flow machines, mixers, and separators, with a focus on performance improvement is of high interest. They usually operate under high Reynolds numbers featuring turbulent flows. In this research, the topology optimization model of turbulent flows is expanded by adapting the Spalart-Allmaras (SA) model with the Rotation/Curvature Correction to consider a density-based material model. This correction improves the turbulence evaluation when rotating frames are considered. The SA model considers the distance to the nearest wall to calculate the turbulent viscosity. However, in the TO, it uses the distance to the nearest solid element, which is calculated by using a novel Eikonal equation with a penalization model. The algorithm is implemented by using a finite element model to solve the state equations. The pyadjoint libraries are used to perform the automatic sensitivity derivation. The objective function considered minimizes energy dissipation. The algorithm is evaluated by performing the optimization of rotating flows with high Reynolds numbers. Several optimized topologies for different domains and angular velocities are shown. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

The research focuses on the design and optimization of rotating fluid devices under high Reynolds numbers, using a modified SA model and density-based material model. The analysis considers the Rotation/Curvature Correction for improved turbulence evaluation in rotating frames. Multiple optimized topologies are demonstrated for rotating flows with different domains and angular velocities.