

	Mechanics På svenska

Project

Two-dimensional turbulence and diffusion of passive scalars therein.

Research Area:

Fluid mechanics

Project Members:

Aurell, E.

Lindborg, E.

Sponsor:

KTH, TFR

Project Description

The project aims at a deeper understanding of turbulent flows that qualify as two-dimensional as a first approximation and diffusion of passive scalars in such flows. The dynamics of the upper atmosphere is the application which will be particularly investigated. Fundamental insight into the dynamics of quasi-two-dimensional flows is important when several problems of great practical importance are dealt with, such as the dispersion of pollutants, the dynamics of the ozone-layer and weather prediction. The project will tie together the activities of Erik Aurell (Dept. of Math., SU) with the turbulence group at the Dept. of Mech., KTH, in particular Erik Lindborg, and will greatly benefit from the combination of contributions from these two Departments. The methods used are: fundamental analysis of the governing equations, development of simple mathematical models, direct numerical simulations (DNS), analysis based on the MOZAIC data set (wind and temperature measurements from over 6000 flights in the upper atmosphere) and finally a systematic comparison between the results from modeling, DNS and data analysis.

Publications related to the project

Year	Title
2000	Determining the Cascade of Passive Scalar Variance in the Lower Stratosphere Phys. Lett. 85 5663-5666 (Published)
2000	The kinetic energy spectrum of the two-dimensional enstrophy cascade The kinetic energy spectrum of the two-dimensional enstrophy cascade Phys. Fluids 12 945-947 (Published)
1999	Correction to the four-fifths law due to variations of the dissipation. Phys. Fluids 388 259-288 (Accepted)
1998	Can the atmospheric kinetic energy spectrum be explained by two-dimensional turbulence? J. Fluid Mech. (Accepted)

Internal Reports related to the project

Year	Title	Document Type