| Abstract: | Interaction of vortex rings with solid is an important research
topic of hydrodynamic. In this study, a multiple-relaxation time
(MRT) lattice Boltzmann method (LBM) is used to investigate the flow
of a vortex ring impacting spheroidal particles. The MRT-LBM is
validated through the cases of vortex ring impacting a flat wall.
The vortex evolution due to particle size, the aspect ratio of a
prolate particle, as well as Reynolds $(Re)$ number are discussed in
detail. When the vortex ring impacting a stationary sphere, the
primary and secondary vortex rings wrap around each other,
which is different from the situation of the vortex ring
impacting a plate. For the vortex ring impacting with a prolate
spheroid, the secondary vortex ring stretches mainly along the long
axis of the ellipsoid particle. However, it is found that after the
vortex wrapping stage, the primary vortex recovers along the short
axis of the particle faster than that in the long axis,
i.e., the primary vortex ring stretches mainly along the short axis
of the particle. That has never been addressed in the literature. |
