Stationary vs Rotating Patterns

The following pairs of images illustrate the asymmetry of cell shape introduced by rotation. In each case, a flame front is formed over a circular, porous-plug burner. The fuel is isobutane mixed with air. The cells lose their symmetrical shape when they begin to rotate.

Stationary pattern of 2 cells compared with a pattern of 2 cells rotating in a clockwise direction:

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A stationary ring of 6 cells compared with a ring of 6 cells rotating in the clockwise direction:

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A stationary pattern with an outer ring of 9 cells surrounding an inner ring containing 2 cells. The right image shows a stationary ring of 10 cells surrounding a ring of 2 cells rotating in the counter-clockwise direction.

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