Average evolution and size-topology relations for coarsening 2d dry foams

Two-dimensional dry foams coarsen according to the von Neumann law as dA / dt ∝ ( n − 6) where is number of sides a bubble with area A . Such reach self-similar scaling state and side-number distributions are stationary. Combining self-similarity law, we derive time derivatives moments distribution relation connecting averages that weighted by powers area. To test these predictions, collect analyze high precision image data for large bubbles squashed between parallel acrylic plates allowed into state. We find good agreement ranging from 2–20.