Solitary waves on falling liquid films in the inertia-dominated regime

File Description SizeFormat 
solitary_waves_on_falling_liquid_films_in_the_inertiadominated_regime.pdfPublished version1.18 MBAdobe PDFView/Open
Title: Solitary waves on falling liquid films in the inertia-dominated regime
Authors: Denner, F
Charogiannis, A
Pradas, M
Markides, C
Van Wachem, B
Kalliadasis, S
Item Type: Journal Article
Abstract: We offer new insights and results on the hydrodynamics of solitary waves on inertiadominated falling liquid films using a combination of experimental measurements, direct numerical simulations (DNS) and low-dimensional (LD) modelling. The DNS are shown to be in very good agreement with experimental measurements in terms of the main wave characteristics and velocity profiles over the entire range of investigated Reynolds numbers. And, surprisingly, the LD model is found to predict accurately the film height even for inertia-dominated films with high Reynolds numbers. Based on a detailed analysis of the flow field within the liquid film, the hydrodynamic mechanism responsible for a constant, or even reducing, maximum film height when the Reynolds number increases above a critical value is identified, and reasons why no flow reversal is observed underneath the wave trough above a critical Reynolds number are proposed. The saturation of the maximum film height is shown to be linked to a reduced effective inertia acting on the solitary waves as a result of flow recirculation in the main wave hump and in the moving frame of reference. Nevertheless, the velocity profile at the crest of the solitary waves remains parabolic and self-similar even after the onset of flow recirculation. The upper limit of the Reynolds number with respect to flow reversal is primarily the result of steeper solitary waves at high Reynolds numbers, which leads to larger streamwise pressure gradients that counter flow reversal. Our results should be of interest in the optimisation of the heat and mass transport characteristics of falling liquid films and can also serve as a benchmark for future model development.
Issue Date: 4-Jan-2018
Date of Acceptance: 16-Nov-2017
ISSN: 0022-1120
Publisher: Cambridge University Press (CUP)
Start Page: 491
End Page: 519
Journal / Book Title: Journal of Fluid Mechanics
Volume: 837
Copyright Statement: © 2018 Cambridge University Press This is an Open Access article, distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives licence (, which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is unaltered and is properly cited. The written permission of Cambridge University Press must be obtained for commercial re-use or in order to create a derivative work.
Sponsor/Funder: Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Funder's Grant Number: EP/K008595/1
Keywords: 01 Mathematical Sciences
09 Engineering
Fluids & Plasmas
Publication Status: Published
Appears in Collections:Faculty of Engineering
Mechanical Engineering
Chemical Engineering

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Creative Commons