In an intriguing paper (1), Maroteaux, Llory, Le Coz, and Habchi presented a separation criterion for a liquid film from sharp edges in a high-speed air flow. According to their model, the film of thickness $hf$ and velocity $Uf$ separates from a sharp edge of angle $\alpha $ if $\alpha >\alpha crit$. The relation obtained for the critical angle isDisplay Formula

$\alpha crit=Uf\omega maxhflog(\delta \delta 0)crit$

(1)

where

$\delta \u2215\delta 0$ is the amplitude ratio of the final to the initial perturbation of the film surface. When the wave amplitude reaches a critical value, the film stripping from an edge occurs. The critical value

$(\delta \u2215\delta 0)crit$ is set equal to 20 as the best fit for their experimental data. The frequency

$\omega max$ is defined as the most unstable perturbation growth rate that causes the film separation. This maximum frequency is computed from the dispersion relation of Jain and Ruckenstein (JR) (

2). The results of 12 tests with dodecane film flowing on springboard or straight step are reported. The geometrical edge angle

$\alpha $ is equal to

$135deg$ for all tests. The maximum film thickness

$hf$ is measured while the film velocity

$Uf$ is estimated. The fact of stripping is established from the visual observations. If the critical angle, computed from Eq.

1, takes values that are inferior to

$135deg$, the theory assumes to predict stripping. The experimental data are summarized in Table

1.