Ultimate regime of convection: Robustness to poor thermal reservoirs

Abstract

A transition to Kraichnan ultimate regime of convection has been reported in very high Rayleigh numbers experiments, but not in all of them. These apparently contradictory results can be explained by a recent phenomenological model that accounts for the nonideality of the plate thermal properties [Chillà, Phys. Fluids 16, 2452 (2004)]. In this paper, we present a direct test of this model, using a low conductivity plate. We found an unaltered transition, not compatible with the model's predictions. © 2005 American Institute of Physics.