Bulk scaling in wall-bounded and homogeneous vertical natural convection

Abstract

Previous numerical studies on homogeneous Rayleigh-Bénard convection, which is Rayleigh-Bénard convection (RBC) without walls, and therefore without boundary layers, have revealed a scaling regime that is consistent with theoretical predictions of bulk-dominated thermal convection. In this so-called asymptotic regime, previous studies have predicted that the Nusselt number (Nu) and the Reynolds number (Re) vary with the Rayleigh number (Ra) according to Nu∼Ra1/2 and Re∼Ra1/2 at small Prandtl numbers (Pr). In this study, we consider a flow that is similar to RBC but with the direction of temperature gradient perpendicular to gravity instead of parallel to it; we refer to this configuration as..