Volume penalization method for simulating flows around a rotating solid with multiple reference frame and sliding mesh

TL;DR

This paper develops a volume penalization method combined with multiple reference frame and sliding mesh techniques to simulate flows around rotating solids with complex geometries, validated against traditional body-fitted methods.

Contribution

It introduces a unified immersed-boundary approach using VPM with MRF and SLM for accurate flow simulation around rotating objects with complex shapes.

Findings

Pressure drop and torque predictions deviate by about 5% from body-fitted methods.

The proposed method effectively simulates flows around rotating geometries.

Validation confirms the method's accuracy and potential for turbomachinery applications.

Abstract

Despite the significant role of turbomachinery in fluid-based energy transfer, precise simulation of rotating solid objects with complex geometry is a challenging task. In the present study, the volume penalization method (VPM) is combined with multiple reference frame (MRF) and sliding mesh (SLM), respectively, so as to develop immersed-boundary approaches for simulating flows around a rotating solid. The level-set function is adopted to represent arbitrary geometries embedded in Cartesian grids. The VPM body-forcing terms in the momentum equation are proposed for MRF and SLM, respectively, so as to build unified governing equations for both fluid and solid regions. The flows around a rotating cuboid under various rotating speeds are simulated by the present schemes, namely, VPM with MRF, and VPM with SLM, and compared to corresponding simulations by the body-fitted method (BFM). The results suggest the relative deviations of predicted pressure drop and torque between the present VPM and BFM are around 5%, demonstrating the validity of the present VPM.