Published online by Cambridge University Press: 26 April 2006
The title problem, which is an important early element of the mechanism of the development of a surface oil flow visualization picture, is studied by a linear stability analysis that predicts the most strongly amplified wavenumber of transverse surface waves as a function of Reynolds number, surface tension, film viscosity and initial thickness of the film. Wall scaling virtually removes the additional dependence on Reynolds number. In a simple experiment the observed wavenumber agrees with the predicted most strongly amplified value to within the experimental accuracy.