Abstract:
Surface tension changes resulting from a periodic local compression and expansion of a surface
propagate over the available surface area. Whether or not the extent of deformation is uniform over
the whole area is determined by the value of a dimensionless parameter, the wave propagation
number. Uniformity increases with increasingly clastic surface behaviour and with decreasing
frequency, area of the surface, and bulk density and viscosity.
A number of numerical examples is given. The significance of surface uniformity for the deter
mination of the surface dilational modulus and for stability of thin films is discussed.
