 |
| Titel |
Cascade processes in plane flows |
| VerfasserIn |
R. Castilla, G. Garzón, J. M. Redondo |
| Konferenz |
EGU General Assembly 2009
|
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 11 (2009) |
| Datensatznummer |
250020184
|
|
|
|
|
|
| Zusammenfassung |
| The diffusion of a tracer in a two dimensional turbulent flow which is forced by non-homogeneous distribution is dominated by the structures in
the flow. In case of acceleration producing baroclinic vorticity due to density differences, Instabilities such as the Rayleigh-Taylor [1] or the Kelvin-Helmholtz appear. These are investigated using multi-fractal techniques, analyzing mixedness, [2], ESS [3]and higher order
order structure functions, that indicate both direct or inverse cascades towards the large scales and producing spectral variations [4]. These can be studied numerically using both DNS and Kinematic Simulation (KS) forcing a set spectra. The direct comparison of the Eulerian and Lagrangian features The mixing processes are compared by mapping the different intermittency (Obtained by relating it to the sixth and third order structure function scaling exponents) and to the measured maximum Fractal dimension showing that and there are a set of functions that provide a complex intermittency scaling.
[1] Redondo J.M. and Garzon G. (2004) Multifractal structure
and intermittency in Rayleigh-Taylor Driven Fronts. Ed. S. Dalziel
www.damtp.cam.ac.uk/iwpctm9/proceedings/IWPCTM9/Papers/Programme.htm
[2] Redondo, J.M. and Cantalapiedra I.R. (1993) Mixing in Horizontally Heterogeneous Flows. Jour. Flow Turbulence and Combustion. 51. 217-222.
[3] Benzi et al. (1995) On the scaling of 3D homogeneous and isotropic turbulence, Physica D 80, 385-398.
[4] Castilla R, Redondo J.M., Gamez P.J., Babiano A. (2007) Coherent vortices and Lagrangian Dynamics in 2D Turbulence. Non-Linear Processes in Geophysics 14. 139-151. |
|
|
|
|
|
|