Long-Wavelength Instability in Surface-Tension-Driven Benard Convection

摘要

Laboratory studies reveal a deformational instability that leads to a drainedregion (dry spot) in an initially flat liquid layer (with a free upper surface)heated uniformly from below. This long-wavelength instability supplantshexagonal convection cells as the primary instability in viscous liquid layersthat are sufficiently thin or are in microgravity. The instability occurs at atemperature gradient 34% smaller than predicted by linear stability theory.Numerical simulations show a drained region qualitatively similar to that seenin the experiment.