Wake and wave resistance on viscous thin films

Wake and wave resistance on viscous thin films
R. Ledesma-Alonso, M. Benzaquen, T. Salez, and E. Raphaël

Journal of Fluid Mechanics, 792 829 (2016)

The effect of an external pressure disturbance, being displaced with a constant speed along the free surface of a viscous thin film, is studied theoretically in the lubrication approximation in one- and two-dimensional geometries. In the comoving frame, the imposed pressure field creates a stationary deformation of the interface – a wake – that spatially vanishes in the far region. The shape of the wake and the way it vanishes depend on both the speed and size of the external source and the properties of the film. The wave resistance, namely the force that has to be externally furnished in order to maintain the wake, is analysed in detail. For finite-size pressure disturbances, it increases with the speed, up to a certain transition value, above which a monotonic decrease occurs. The role of the horizontal extent of the pressure field is studied as well, revealing that for a smaller disturbance the latter transition occurs at a higher speed. Eventually, for a Dirac pressure source, the wave resistance either saturates for a one-dimensional geometry, or diverges for a two-dimensional geometry.

Haut de page


À lire aussi...

Wake and wave resistance on viscous thin films

Wake and wave resistance on viscous thin films R. Ledesma-Alonso, M. Benzaquen, T. Salez, and E. Raphaël Journal of Fluid Mechanics, 792 829 (...) 

> Lire la suite...

Guillaume Durey, doubly rewarded !

Guillaume Durey, PhD student at Gulliver laboratory, EC2M team, was awarded the Fondation Langlois prize for the dissemination of research, (...) 

> Lire la suite...