A numerical solution of the wavy motion on a falling liquid film

Abstract

AbstractWavy motion in falling liquid films enhances heat and mass transfer significantly; therefore, it is important to successfully model this motion for the purpose of heat and mass transfer calculations. In this study, a simple and promising numerical spectral method is developed to solve the periodic wavy film flow equations. With the wave number and the wave celerity specified to be those of the most unstable waves from existing linear stability analysis, the results are found to be good when compared with the existing experimental data for small (Re < 50) and moderate (50 < Re < 150) Reynolds numbers. It is worth noting that many important absorption problems fall in the low and moderate Reynolds number regimes. For higher Reynolds number flows (Re > 150), the solutions are still obtainable but may not be realistic owing to the invalidity of the linear stability analysis and the asymptotic wavy‐state assumption in the high Reynolds number flow.