INVESTIGADORES
MININNI Pablo Daniel
congresos y reuniones científicas
Título:
Large scale structures and energy transfer in hydrodynamic turbulence
Autor/es:
P.D. MININNI, A, ALEXAKIS, Y A. POUQUET
Lugar:
Chicago, Estados Unidos
Reunión:
Congreso; 58th Annual Meeting of the Division of Fluid Mechanics, American Physical Society; 2005
Institución organizadora:
APS
Resumen:
With the help of direct numerical simulations, we investigate the
transfer of energy and triadic interactions in fully developed
forced three-dimensional hydrodynamic turbulence. The assumption
of locality of transfer among the different scales is one of the
building blocks of Kolmogorov (1941) theory of turbulence. We use
simulations on a grid of 1024^3 points of a flow forced with a
Taylor-Green vortex. Reynolds numbers of R=790 (based on the
Taylor lengthscale) are reached. In the steady state, the flow
displays a well defined large scale pattern superimposed with
turbulent fluctuations at small scales. We find that nonlinear
triadic interactions are dominated by their non-local components,
involving widely separated scales, even though the nonlinear
transfer itself is local and the scaling for the energy spectrum
is close to the classical Kolmogorov law. These non-local
interactions with large scales represent 20% of the total energy
flux. The link between these findings and the intermittency of
the small scales, and their consequences for modeling of
turbulent flows are also briefly discussed.