The dissipation rate transport equation remains the most uncertain part of turbulence modeling. The difficulties are increased when external agencies like rotation prevent straightforward dimensional analysis from determining the correct form of the modelled equation. In this work, the dissipation rate transport equation and subgrid scale models for rotating turbulence are derived from an analy...

Direct numerical simulations (DNS) of a shear layer with salt-fingering-favorable stratification have been performed for different Richardson numbers Ri and density ratios Rr. In the absence of shear (Ri 5 ‘), the primary instability is square planform salt fingering, alternating cells of rising and sinking fluid. In the presence of shear, salt fingering takes the form of salt sheets, planar re...

In this article, mixed convection heat transfer of alumina-water nanofluid in an inclined and baffled C-shape enclosure is studied. It is assumed that the flow is laminar and steady. There is no energy production, energy storage and viscous heat dissipation. Furthermore, the nanofluid is considered as a continuous, Newtonian and incompressible fluid. Governing equations are discretized by finit...

Abstract The effect of anharmonicity (coupling) in the field theory generally results dissipation plane waves. It has been appreciated that and ensuing waves can be accompanied by emergence gapped momentum state. Here, we show same lead to a energy state dispersion relation where frequency (energy) gap emerges explicitly. We discuss several notable properties states connections between them.

In a weakly ionized plasma, the evolution of the magnetic field is described by a “generalized Ohm’s law” that includes the Hall effect and the ambipolar diffusion terms. These terms introduce additional spatial and time scales which play a decisive role in the cascading and the dissipation mechanisms in magnetohydrodynamic turbulence. We determine the Kolmogorov dissipation scales for the visc...

Stepped spillways are designed to increase the rate of energy dissipation on the chute and to reduce the size of the downstream energy dissipator. It is essential to predict accurately the turbulent dissipation above the steps for large discharges per unit width corresponding to the skimming flow regime. New measurements were conducted in a large facility with a channel slope of 21.8o and a ste...

The existence of drag reduction by polymer additives, well established for wall-bounded turbulent flows, is controversial in homogeneous, isotropic turbulence. To settle this controversy, we carry out a high-resolution direct numerical simulation of decaying, homogeneous, isotropic turbulence with polymer additives. Our study reveals clear manifestations of drag-reduction-type phenomena: On the...

The total dissipation rate for magnetohydrodynamic (MHD) flows in plane geometry with both velocity and magnetic shear is studied. For some boundary conditions it is shown that the lower bound on the dissipation rate is achieved by the equivalent of Stokes flow for MHD. Using the ‘background method’ (Doering & Constantin, Phys. Rev. Lett. 69, 1648–1651 (1992)) upper bounds for the dissipation r...

The total dissipation rate for magnetohydrodynamic ~MHD! flows in plane geometry with both velocity and magnetic shear is studied. For some boundary conditions it is shown that the lower bound on the dissipation rate is achieved by the equivalent of Stokes flow for MHD. Using the background method @Doering and Constantin, Phys. Rev. Lett. 69, 1648 ~1992!# upper bounds for the dissipation rate a...

Gradient-driven interactions and exchange mechanisms of the reed – open water interface in shallow lake environment were investigated by localised field measurements and detailed data analysis. High frequency 3D flow velocities were recorded in several points throughout a typical interface zone of Lake Fertő. Based on the data the flow distribution, specific discharge, energy dissipation rate, ...