Velocity field and particle position during the sedimentation of 30 circular particles. The white lines stand for the streamlines, while the arrows indicate the flow direction. The simulation was performed on a 540 × 1024 grid.

Dendrites descending in viscous fluid (upper row) with initial orientation “+”, and (bottom row) with initial orientation “×” at downward gravitational acceleration 0.001g. Note the stable behavior until hydrodynamic interaction with the lower wall of the simulation box intervenes, which makes the dendritic particle tumble (see upper row). The simulations were performed on a 4000×5000 grid.

Velocity and concentration fields (upper and bottom rows, respectively) with streamlines during the sedimentation of dendritic particles in viscous fluid and gravity of 0.001g. The simulation was performed on a 2000 × 2000 grid.

Velocity and concentration fields (upper and bottom rows, respectively) during CET via columnar growth from the bottom and nucleation in the upper domain of the simulation box. The simulation was performed on a 4096 × 3072 grid.

Velocity (upper row) and concentration fields (bottom row) during CET induced by a “plume” (a process shown in Fig. 1). The flow in the plume is represented by a wall moving upward. Simulation performed on a 6016 × 4000 grid.