Orientation instability of settling spheroids in a linearly density-stratified fluid

Much work has been done to understand the settling dynamics of spherical particles in a homogeneous and stratified fluid. However, effects shape anisotropy on particle fluid are not completely understood. To this end, we perform numerical simulations for oblate prolate spheroids We present results Galileo number, $Ga$ , range 80–250 Richardson $Ri$ 0–10. find that both reorient edge-wise partially orientations, respectively, as they settle different from steady-state broad-side orientation observed observe reorientation instabilities emerge when velocity magnitudes fall below particular threshold. also report enhancement drag stratification. The torque due buoyancy tries orient spheroid an while hydrodynamic it orientation. Below threshold, dominates; resulting onset instability. Finally, asymmetry distribution baroclinic vorticity generation term around explains