Van der Waals rupture instability of a viscous sheet
= Van der Waals rupture instability of a viscous sheet
{c}
For a viscous sheet of half-thickness $h_0$, attractive <disjoining pressure> $V/h^3$, and <surface tension> $\gamma$, a symmetric Fourier mode of dimensionless wavenumber $K=kh_0$ has a destabilizing molecular contribution and a stabilizing capillary contribution. The ratio
$$
\Gamma=\frac{\gamma h_0^2}{3V}
$$
sets the cutoff $K=\Gamma^{-1/2}$.