Wave turbulence on the surface of a ferrofluid in a magnetic field

François Boyer (1) , Eric Falcon (1)

1 MSC - Matière et Systèmes Complexes

We report the observation of wave turbulence on the surface of a ferrofluid mechanically forced and submitted to a static normal magnetic field. We show that magnetic surface waves arise only above a critical field. The power spectrum of their amplitudes displays a frequency-power law leading to the observation of a magnetic wave turbulence regime which is experimentally shown to involve a 4-wave interaction process. The existence of the regimes of gravity, magnetic and capillary wave turbulence is reported in the phase space parameters as well as a triple point of coexistence of these three regimes. Most of these features are understood using dimensional analysis or the dispersion relation of the ferrohydrodynamics surface waves.

Mots clés: wave turbulence; power spectrum; N-wave interaction process; experiment; fluctuations; distribution; probability density function; PDF; weak turbulence; magnetohydrodynamic waves; ferrofluids; magnetic fluids; triple point; capillary waves; magnetic waves; gravity waves; surface waves

Domaines: Mécanique des fluides [physics.class-ph]; Dynamique Chaotique [nlin.CD]; Mécanique statistique [cond-mat.stat-mech]; Biomécanique [physics.med-ph]; Dynamique des Fluides [physics.flu-dyn]

François Boyer, Eric Falcon. Wave turbulence on the surface of a ferrofluid in a magnetic field. Physical Review Letters, 2008, 101 (24), pp.244502. ⟨10.1103/PhysRevLett.101.244502⟩. ⟨hal-00338272⟩