Instability of a deformed liquid drop in an acoustic field

The flattening and breakup of an axially symmetric liquid drop in an acoustic standing wave field in air have been studied using a boundary integral method. The interaction between the drop and sound field are crucial to this approach. Our computations are focused on the threshold beyond which the drop loses its static equilibrium, and on the dynamic behavior after it loses its equilibrium up to the point when it breaks up. The numerical results are given in terms of drop size and the strength of sound field and are found to be in good agreement with the measurements of others.