Interfacial heat transport in open channel turbulent flows is strongly dependent on surface waves that can appear as a result of the interaction of bulk turbulence with the free surface. The paper describes wave/heat transfer phenomena in inclined turbulent open surface water flows. The experiments were conducted in a regime of transition from ‘‘weak’’ to ‘‘strong’’ turbulence, in which the sta...

The magnetic Reynolds number RM , is defined as the product of a characteristic scale and associated flow speed divided by the microphysical magnetic diffusivity. For laminar flows, RM also approximates the ratio of advective to dissipative terms in the total magnetic energy equation. However, for turbulent flows this latter ratio depends on the energy spectra and approaches unity in a steady s...

The time-dependent vertical structure of cold accretion disks and their thermal stability have been studied with turbulent heat transfer being included. A strong turbulent heat transport enforces a nearly adiabatic stratification and the disk evolves quasi-homologously, although homology is broken by the outer boundary condition. The radiative energy loss scales with the disk’s optical depth τ ...

Free-convection flow through a two-dimensional rectangular box having openings at opposite corners on the vertical walls is investigated numerically, using a commercial Computational Fluid Dynamics (CFD) software package. Convection is induced when the box's ceiling or its floor is imposed with a temperature that is different to that of the ambient fluid, while all other walls are insulated. Th...

We prove a new upper bound on the vertical heat transport in Rayleigh-Bénard convection of the form c Ra 1 3 (lnRa) 2 3 under the assumption that the ratio of Prandtl number over Rayleigh number satisfies Pr Ra ≥ c0 where the non-dimensional constant c0 depends on the aspect ratio of the domain only. This new rigorous bound agrees with the (optimal) Ra 1 3 bound (modulo logarithmic correction) ...

Context. Stellar convection zones are characterized by vigorous high-Reynolds number turbulence at low Prandtl numbers. Aims. We study the dynamo and differential rotation regimes at varying levels of viscous, thermal, and magnetic diffusion. Methods. We perform three-dimensional simulations of stratified fully compressible magnetohydrodynamic convection in rotating spherical wedges at various ...

In this paper, we extend Grossmann and Lohse’s (GL) model [S. D. Lohse, “Thermal convection for large Prandtl numbers,” Phys. Rev. Lett. 86, 3316 (2001)] the predictions of Reynolds number (Re) Nusselt (Nu) in turbulent Rayleigh–Bénard convection. Toward objective, use functional forms prefactors dissipation rates bulk boundary layers. The arise due to inhibition nonlinear interactions presence...