Direct numerical simulation of flow past a solid particle: Influence of streamline curvature and particle non-sphericity

摘要

Conventional point-particle models for fluid-solid two-phase flows are mainly based on the analysis of the fluid force on a sphere in a uniform stream or a homogeneous shear flow. Their applicability to the flows with (non-zero) streamline curvature and non-spherical particles is yet to be established. In particle segregation in curved flows, the effects of streamline curvature and particle shapes may become significant. In the present study, the hydrodynamic force on a single spherical/spheroidal particle in uniform and curved flow is investigated. The flow around a solid particle is simulated by an immersed-boundary method of a body force type, which has been developed by the authors. The results demonstrate that the spheroidal particle receives higher drag force than the spherical particle. On the other hand, though the effect of the streamline curvature on the fluid force is not clearly observed, the spherical particle rotates only in curved flow.