  We address an experimental investigation of evaporation waves. These waves
appear when a liquid contained in a vertical glass tube is suddenly
depressurized from a high initial pressure down to the atmospheric one. The
state of the liquid after the release of the pressure, ambient pressure and the
initial temperature, is well known to be metastable when the corresponding
stable state is vapour. For moderately large evaporation rates (moderately
large initial to ambient pressure ratios), the initially flat vapour-liquid
interface ultimately evolves into highly corrugated front which propagates
downwards into the liquid with a well defined mean velocity. This mean velocity
turns out to be a function of the ratio between the initial and the ambient
pressures. In addition, it has been found that for lower pressure ratios, the
instability is not able to develop an evaporation wave but nevertheless leads
to a somewhat more complex behavior than the simple surface evaporation as it
is shown in the accompanying fluid dynamics video.
