Observation of the 1/2 power law in Rayleigh-Bénard convection

Philippe-Emmanuel Roche (1) , Bernard Castaing (2) , Benoît Chabaud (1) , Bernard Hébral (1)

1 CRTBT - Centre de Recherches sur les Très Basses Températures
2 Phys-ENS - Laboratoire de Physique de l'ENS Lyon

The 1/2 power law is reported in a {R}ayleigh-{B}énard experiment: Nu~?Ra/sup 1/2/, where Ra and Nu are the {R}ayleigh and {N}usselt numbers. This observation is coherent with the predictions of the ultimate convection regime, characterized by fully turbulent heat transfers. Ordered rough boundaries are used to cancel the correction due to the thickness variation of the viscous sublayer, and the observation of the asymptotic regime is therefore possible. This result supports the interpretation of a laminar-turbulent boundary-layer transition to account for the observation of Chavanne et al. of a new regime [X. Chavanne et al., Phys. Rev. Lett. 79, 3648 (1997)].

Domaines: Autre [cond-mat.other]; Dynamique des Fluides [physics.flu-dyn]

Philippe-Emmanuel Roche, Bernard Castaing, Benoît Chabaud, Bernard Hébral. Observation of the 1/2 power law in Rayleigh-Bénard convection. Physical Review E : Statistical, Nonlinear, and Soft Matter Physics, 2001, 63, pp.045303(R). ⟨hal-00521146⟩