Fig. 2.

Biasing pattern formation in fluid dynamics. Simulations of Rayleigh–Bernard convection in a pan of fluid heated from below and cooled from above. Convection organizes into spinning cylinders of rising hot and falling cool fluid, which look like stripes when viewed from above. The orientation of the stripe patterns is usually random but is biased by injection of fluid along a particular orientation, shown by the straight bars in the first (T = 0) row. (a and b) Two biasing experiments during 200 time steps. (c) A conflict set up by two orientated injections, one 90% as strong as the other. The induced patterns compete, but the one induced by the stronger injection wins out. [Reproduced with permission from ref. 21 (Copyright 2004, Springer Science and Business Media).]