A viscous compressible model of soap film flow and its equivalence with the Navier-Stokes equations

Petri Fast

Published 2005-11-20Version 1

We present a quasi-two dimensional model of flowing soap films that bears striking similarity to the compressible Navier-Stokes equations. The variation in soap film thickness that is commonly used for flow visualization in experiments is analogous to density variations in the Navier-Stokes equations. When the soap film flow velocity is comparable to the Marangoni elastic wave velocity we recover the compressible Navier-Stokes equations and the soap film behaves like a two-dimensional isothermal viscous gas.