Mehrdad's Bed

Qualitative Benchmarking: Ordered bubbling via periodic fluidization

Typical random bubbling patterns under uniform fluidization can be driven to ordered states under periodic fluidization. At certain system sizes and conditions, a regular left-right alternating single bubble pattern can be achieved. The animation, rendered in Blender, shows time 10s to 15s played back at 1/4x speed. Simulation considers 166k particles run with MFiX Exa 19.08 using 32 CPU cores.

Animation courtesy of Justin Weber & William D. Fullmer, Multiphase Flow Science Group, NETL, Morgantown WV.

Clustering in the HCS

Qualitative Benchmarking: Dissipation induced clustering instability

A homogeneous cooling system (HCS) of size 256 x 256 x 8 particle diameters containing 50k particles (concentration ~5%) with an initial thermal Reynolds number of 20, restitution coefficient of 0.8 and particle-fluid density ratio of 1000. The system is significantly above the critical length scale for the onset of clustering causing the originally homogeneous state to develop spatial inhomogeneities. Animation shows particle velocity magnitude ranging from 0.0116 m/s (white) to 0 (black). Simulation run with MFiX Exa 19.08 using 16 CPU cores.

Animation courtesy of William D. Fullmer, Multiphase Flow Science Group, NETL, Morgantown WV.