Laminar film flow along a periodic wall

Laminar, gravity-driven flow of a liquid down an inclined wall with large-a mplitude sinusoidal corrugations is studied numerically by a spectral spati al discretization method. The synchronous resonance between the wall and th e free surface is investigated for corrugations with wavelength 0.002 m, wh ich - according to linear theory - lead to strongest interaction. Free surf ace profile and flow structure are studied as a function of the film Reynol ds number and the wall amplitude. Streamline patterns are computed and cond itions leading to flow reversal are established. The distribution of the sh ear stress along the wall and of the normal velocity gradient close to the free surface are computed and related to heat/mass transport.