title: Nodal analysis of nonlinear behavior of the instability at a fluid interface.
abstract: In interface instabilities, deformations first grow exponentially, then enter a nonlinear regime affecting amplitude and symmetry. Most extant studies have focused on amplitude alone. Here, we study a 2D Rayleigh-Taylor instability for an initial sinusoidal deformation, analyzing its amplitude and asymmetry over time. For the latter, we define a metric based on the zero crossings of the interface. We develop a weakly nonlinear model and compare it to experimental data. It shows that our asymmetry metric complements the amplitude for an improved description of the instabilities' nonlinear phases.
authors.affiliation: LOMC laboratory, Université du Havre/CNRS, UMR 6294, 76000 Le Havre, France.|UPMC Université Paris 06, F-75005 Paris, France.|FAST laboratory, Université Paris 11/CNRS, UMR 7608, 91400 Orsay, France.
authors.forename: M-C
authors.initials: MC
authors.lastname: Renoult
authors.affiliation: UPMC Université Paris 06, F-75005 Paris, France.|Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079 USA.
authors.forename: C
authors.initials: C
authors.lastname: Rosenblatt
authors.affiliation: UPMC Université Paris 06, F-75005 Paris, France.|FAST laboratory, Université Paris 11/CNRS, UMR 7608, 91400 Orsay, France.|Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106-7079 USA.
authors.forename: P
authors.initials: P
authors.lastname: Carles