I played around with simulations of colloidal suspensions. Here are some results:
The method is called multi-particle-collision dynamics and is suited for fluids and particles on mesoscopic scales – the scales between stochastic microscopic motion and large fluid-dynamical structures. The experimental setup of the animations you see here is a box filled with a two-dimensional fluid subject to gravitation. The box is periodic in the x-direction. Inside the fluid are small particles with a higher mass density such that one observes sedimentation. An important feature of the simulation technique is that it explicitly enables hydrodynamic interactions. This results in the nice vortex like pattern during the process.
Here are some more animations with different parameters: