title: Gap size effects for the Kelvin-Helmholtz instability in a Hele-Shaw cell.
abstract: We report experimental results for the Kelvin-Helmholtz instability between two immiscible fluids in parallel flow in a Hele-Shaw cell. We focus our interest on the influence of the gap size between the walls on the instability characteristics. Experimental results show that the instability threshold, the critical wavelength, the phase velocity, and the spatial growth rate depend on this gap size. These results are compared to both the previous two-dimensional analysis of Gondret and Rabaud [Phys. Fluids 9, 3267 (1997)] and the three-dimensional analysis recently derived by Plouraboué and Hinch [Phys. Fluids (to be published)], showing that the agreement is still not complete especially when gap size increases.
authors.affiliation: Laboratoire Fluides, Automatique et Systèmes Thermiques, Universités Pierre & Marie Curie et Paris-Sud, CNRS (UMR 7608), Bâtiment 502, Campus Universitaire, 91405 Orsay Cedex, France.
authors.forename: L
authors.initials: L
authors.lastname: Meignin
authors.forename: P
authors.initials: P
authors.lastname: Ern
authors.forename: P
authors.initials: P
authors.lastname: Gondret
authors.forename: M
authors.initials: M
authors.lastname: Rabaud