KEYNOTE Seminar: Prof. Christian Ruyer-Quil, Université de Savoie - Chambéry


Thursday, May 21, 2015 - 13:15 to 14:15

Prof. Christian Ruyer-Quil

Université de Savoie - Chambéry, France

“Dynamics of a falling liquid film”

Christian is our Guest of Honour for the TPLS Mini Symposium and Version 2 Launch

Falling film flows are encountered in many industrial applications and still form the state-of-the-art technology in several chemical engineering processes because of their reduced resistance to heat and mass transfer. For instance, absorbers and generators are currently designed using falling liquid films on vertical plates whenever pressure drops in the gas phase is critical. 

Optimization of such apparatuses requires the knowledge and control of the wavy regime of falling liquid films as waves are well known to intensify the heat and mass transfer both at the wall and at the free surface. Such a regime is characterized by the onset of a weakly disordered state organized around  large-amplitude solitary waves in interaction. The long-wave nature of the waves and the laminar state of the flow enable to derive reduced sets of equations or models that are amenable to thorough analytic investigations.

This talks reviews the phenomenology of falling film flows and discusses recent low-dimensional modeling attempts. Two situations will be considered in particular: (i) sheared falling films and flooding phenomena, (ii) heated falling films and the interplay between hydrodynamic and Marangoni instabilities.  

Christian Ruyer-Quil graduated from Ecole Polytechnique in 1995. He received his PhD in mechanical engineering from Ecole Polytechnique in 1999 where he was trained under the direction of Paul Manneville. He joined the Mechanical Engineering Department of Université Pierre and Marie Curie (Paris 6) in 2000. He was appointed Professor at Université de Savoie Mont-Blanc (Chambéry) in 2013. He is a Junior Member of the Institut Universitaire de France. 

Christian is interested in hydrodynamic instabilities, free-surface flows and two-phase flows. He developed a consistent Saint-Venant approach to deal with long-wave instabilities and applied this approach to the Kapitza instability of falling films for Newtonian and non-Newtonian fluids, and he analyzed its coupling with the Marangoni instability (heated films) and the Rayleigh-Plateau instabilities (films running down fibers). At present he works on the intensification of transfer in falling-film exchangers.

Isotherms under a solitary wave running vertically on an heated water film (Re=2, Bi=0.1, Pr=7). A thermal boundary layer promoted by a convection roll is observable close to the wave crest.
Prof. Christian Ruyer-Quil