LAMINAR-FILM FLOW DOWN A WAVY INCLINE

Laminar how of a liquid, down an inclined wall with sinusoidal corruga tions, is considered. A linear analysis, valid for small-amplitude dis turbances but arbitrary wavelength and Re number, leads to an Orr-Somm erfeld type equation with nonhomogeneous boundary conditions. The free -surface amplitude and phase relative to the wall are examined. In a r ange of Re numbers, a resonance phenomenon is calculated, leading to a mplification of the wall corrugations. This behavior has not been enco untered in previous analyses of thin film flow, based on the Stokes ap proximation. Copyright (C) 1996 Elsevier Science Ltd.