title: Search for the "ultimate state" in turbulent Rayleigh-Bénard convection.
abstract: Measurements of the Nusselt number Nu and of temperature variations DeltaTb in the bulk fluid are reported for turbulent Rayleigh-Bénard convection of a cylindrical sample. They cover the Rayleigh-number range 10(9) less than or similar to Ra less than or similar to 3x10(14) using He (Prandtl number Pr=0.67), N2 (Pr=0.72) and SF6 (Pr=0.79 to 0.84) at pressures up to 15 bars and near-ambient temperatures. The sample had a height L=2.24 m and diameter D=1.12 m and was located in a new High-Pressure Convection Facility (HPCF) at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany. The data do not show the transition to an "ultimate regime" reported by Chavanne et al. and are consistent with the measurements of Niemela et al.
authors: LSGC CNRS-GROUPE ENSIC, BP 451, 54001 Nancy Cedex, France.
authors: Denis
authors: D
authors: Funfschilling
authors: Eberhard
authors: E
authors: Bodenschatz
authors: Guenter
authors: G
authors: Ahlers