Passive scalar evolution

Brandenburg, A., Käpylä, P., & Mohammed, A.: 2004, ``Non-Fickian diffusion and tau-approximation from numerical turbulence,'' Phys. Fluids 16, 1020-1027 (astro-ph/0306521, ADS, PDF)

Decay calculation

initial hat function: kf=2.2, 256³ AVI (1.0M), mpeg (445k)

initial hat function: kf=1.5, 256³ AVI (10M), mpeg (5.1M)

initial gaussian: kf=5.1, 256³ AVI (12M), mpeg (8.1M)

initial gaussian: kf=1.5, 256³ AVI (4.9M), mpeg (4.4M)

With imposed gradient

forcing wavenumber: kf=1.5, 256³ AVI (4.6M), mpeg (1.9M)

forcing wavenumber: kf=5.1, 256³ AVI (4.6M), mpeg (1.8M)

forcing wavenumber: kf=1.5, 512³ AVI (3.0M), mpeg (1.2M)

forcing wavenumber: kf=1.5, 512³ AVI (3.8M), mpeg (1.7M)

Corresponding velocity (uz component)

forcing wavenumber: kf=1.5, 512³ AVI (3.8M), mpeg (1.6M)

With rotation and imposed gradient

forcing wavenumber: kf=1.5, 128³ AVI (158M), mpeg (62M)