• Corpus ID: 210064487

Evolution of the turbulence interface in flows with and without stable stratification

  title={Evolution of the turbulence interface in flows with and without stable stratification},
  author={Marius M. Neamtu-Halic and Dominik Krug and Jean-Paul Mollicone and Maarten van Reeuwijk and George Haller and Markus Holzner},
  journal={arXiv: Fluid Dynamics},
The surface area of turbulent/non-turbulent interfaces (TNTIs) is continuously produced and destroyed via stretching and curvature/propagation effects. Here, the mechanisms responsible for TNTI area growth and destruction are investigated in a turbulent flow with and without stable stratification through the time evolution equation of the TNTI area. We show that both terms have broad distributions and may locally contribute to either production or destruction. On average, however, the area… 

Role of vortical structures for enstrophy and scalar transport in flows with and without stable stratification

We investigate the enstrophy dynamics in relation to objective Eulerian coherent structures (OECSs) and their impact on the enstrophy and scalar transport near the turbulent/non-turbulent interface



Signature of large-scale motions on turbulent/non-turbulent interface in boundary layers

The effect of large-scale motions (LSMs) on the turbulent/non-turbulent (T/NT) interface is examined in a turbulent boundary layer. Using flow fields from direct numerical simulation, the shape of

Lagrangian coherent structures and entrainment near the turbulent/non-turbulent interface of a gravity current

In this paper, we employ the theory of Lagrangian coherent structures for three-dimensional vortex eduction and investigate the effect of large-scale vortical structures on the

Interfacial Layers Between Regions of Different Turbulence Intensity

Recent developments in the physics and modeling of interfacial layers between regions with different turbulent intensities are reviewed. The flow dynamics across these layers governs exchanges of

The turbulent/non-turbulent interface bounding a far wake

The velocity fields of a turbulent wake behind a flat plate obtained from the direct numerical simulations of Moser et al. (1998) are used to study the structure of the flow in the intermittent zone

Some characteristics of entrainment at a cylindrical turbulence boundary

Over the last 30 years, turbulent entrainment has come to be viewed as a large-scale process, directed by coherent structures, and described as engulfing. With turbulence simulations, we examined the

A Lagrangian investigation of the small-scale features of turbulent entrainment through particle tracking and direct numerical simulation

We report an analysis of small-scale enstrophy ω2 and rate of strain s2 dynamics in the proximity of the turbulent/non-turbulent interface in a flow without strong mean shear. The techniques used are

The mechanism of entrainment in free turbulent flows

  • A. Townsend
  • Environmental Science
    Journal of Fluid Mechanics
  • 1966
A considerable quantity of observations and measurements exists concerning the phenomenon of intermittency which is connected closely with the entrainment process in free turbulent flows. A number of

The entrainment interface

A theory is developed to describe the evolution of the entrainment interface in turbulent flow, in which the surface is convoluted by the large-scale eddies of the motion and at the same time

The role of coherent vortices near the turbulent/non-turbulent interface in a planar jet

  • C. B. da SilvaR. J. N. dos Reis
  • Physics, Environmental Science
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2011
The coherent vortices in the proximity of the T/NT interface are preferentially aligned with the tangent to the T-NT interface and are responsible for the viscous dissipation of kinetic energy near theT/NT interfaces and to the characteristic shape of the enstrophy viscous diffusion observed at that location.

Global and local aspects of entrainment in temporal plumes

To date, the understanding of the role buoyancy plays in the entrainment process in unstable configurations such as turbulent plumes remains incomplete. Towards addressing this question, we set up a