Stability and fluctuations of a spatially periodic convective flow

Y. Pomeau , P. Manneville

Using a model equation we analyze the onset of convection for a roll instability. The wavelength increase follows from a variational approach. For certain wavelengths, phase diffusion turns out to be unstable against compression (or dilatation) and torsion of the rolls. Thermal phase fluctuations induce a tiny brownian motion of the structure which should be observable in carefully designed experiments such as Rayleigh-Bénard in liquid helium or Carr-Helfrich in nematic liquid crystals.

Mots clés: Brownian motion; convection; flow instability; fluctuations; variational techniques; spatially periodic convective flow; model equation; roll instability; variational approach; phase diffusion; compression; torsion

Domaines: Articles anciens

Y. Pomeau, P. Manneville. Stability and fluctuations of a spatially periodic convective flow. Journal de Physique Lettres, 1979, 40 (23), pp.609-612. ⟨10.1051/jphyslet:019790040023060900⟩. ⟨jpa-00231699⟩