Tutorial cases for the lecture 'Introduction to Particle Simulation' at JKU.
Vortex shedding after a cylinder at Re = 200 computed with OpenFOAM. After a spin-up phase, a periodic Kármán vortex street develops.
Particles settling in a box with an obstacle and draining through a hole in the bottom. After sufficient time, only particles in the corners remain in the domain and demonstrate the material's angle of repose.
Initial state of a hopper before material reaches the outlet and clogs it within a few time steps. Increasing the outlet diameter or making the walls steeper and/or smoother enhances flowability.
Resolved CFD-DEM: two particles settling in a liquid column. The upper particle follows the lower one in its wake and finally catches up. The details of the fluid-mediated particle-particle interaction can only be captured with highly resolved simulations.
Unresolved CFD-DEM: a bubbling fluidized bed with an obstacle. The inflow velocity increases from 0 m/s to its final value 1.6 m/s over the course of 1.0 s. First, the particles form a packed, immobile bed. Only when the gas velocity exceeds the fluidization velocity, particles start to move and form a transient pattern of voids and clusters.
Two-fluid model: a turbulent fluidized bed with significant bed expansion. The large gas velocity transports particles high up in the container, creating a pattern of clusters with extended dilute regions between them. The vectors illustrate the gas flow, bypassing dense clusters of particles.