title: Prandtl-Number Dependence of Heat Transport in Laminar Horizontal Convection.
abstract: We report the Prandtl-number (Pr) and Rayleigh-number (Ra) dependencies of the Reynolds number (Re) and mean convective heat transport, measured by the Nusselt number (Nu), in horizontal convection (HC) systems, where the heat supply and removal are provided exclusively through a lower horizontal surface of a fluid layer. For laminar HC, we find that Re∼Ra^{2/5}Pr^{-4/5}, Nu∼Ra^{1/5}Pr^{1/10} with a transition to Re∼Ra^{1/2}Pr^{-1}, Nu∼Ra^{1/4}Pr^{0} for large Pr. The results are based on direct numerical simulations for Ra from 3×10^{8} to 5×10^{10} and Pr from 0.05 to 50 and are explained by applying the Grossmann-Lohse approach [J. Fluid Mech. 407, 27 (2000)] transferred from the case of Rayleigh-Bénard convection to the case of laminar HC.
authors.affiliation: Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, D-37077 Göttingen, Germany.
authors.forename: Olga
authors.initials: O
authors.lastname: Shishkina
authors.affiliation: Max Planck Institute for Dynamics and Self-Organization, Am Fassberg 17, D-37077 Göttingen, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Wagner