Lehrstuhl fürNumerische Mathematik 2 LBM

Implementation of LBM

• Using Matlab → see code

• Using Python →

Difference Matlab 0.042 s/iter and Python 0.0037 s/iter → simulation with 100 000time steps: 1h 10min in Matlab and 6.2 min in Python.

JJ J I II 0 1 2

Lehrstuhl fürNumerische Mathematik 2 LBM

Simulation

• Different geometries

4)

3)

• Different boundary conditionsinflow, outflow, no-slip, free-slip, ...

JJ J I II 0 1 2

Lehrstuhl fürNumerische Mathematik 2 LBM

Simulation

• Flow around a cylinder inflow (left), outflow (right) and periodic bc’s (below, top)

Fig. Magnitude of the velocity after 0, 17 000, 21 000 and 27 000 time steps.

→ Video

JJ J I II 0 1 2

Lehrstuhl fürNumerische Mathematik 2 LBM

Simulation

• Rayleigh-Taylor Instability heavy fluid initially on top of a light fluid

Fig. ρ of the heavy fluid after 16 000, 48 000,69 000 and 155 000 time steps.

→ Video

JJ J I II 0 1 2

Lehrstuhl fürNumerische Mathematik 2 LBM

Simplified porous media setting

Rotating view of flow over random sphere pack

Geometry setup: PE rigid multi-body physics engine [Ruede, Iglberger, Preclik 09-14]

JJ J I II 0 1 2