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Journal of Flow Visualization and Image Processing
SJR: 0.161 SNIP: 0.312 CiteScore™: 0.1

ISSN Imprimir: 1065-3090
ISSN On-line: 1940-4336

Journal of Flow Visualization and Image Processing

DOI: 10.1615/JFlowVisImageProc.2012006261
pages 139-160

TURBULENT EVENTS IN A WALL-BOUNDED TURBULENT FLOW

Giancarlo Alfonsi
Fluid Dynamics Laboratory, Universita della Calabria, Via P. Bucci 42b, 87036 Rende (Cosenza), Italy
Stefania A. Ciliberti
Fluid Dynamics Laboratory, Universita della Calabria, Via P. Bucci 42b, 87036 Rende (Cosenza), Italy
Marco Mancini
Fluid Dynamics Laboratory, Universita della Calabria, Via P. Bucci 42b, 87036 Rende (Cosenza), Italy
Leonardo Primavera
Fluid Dynamics Laboratory, Universita della Calabria, Via P. Bucci, Cubo 42b, 87036 Rende (Cosenza), Italy

RESUMO

The interaction between vortical structures and turbulent events in the wall region of a turbulent channel flow is investigated numerically. The system of the incompressible Navier-Stokes equations is integrated by using a mixed spectral finite-difference numerical technique, following the procedure of direct numerical simulation (DNS) of turbulence. The value of the Reynolds number based on the wall-shear velocity and channel half-height is Reτ = 200. A specially assembled computing machine is used for calculations, including one Intel i7 quad-core processor and one Nvidia C-1060 Tesla device programmed using the CUDA paradigm. The swirling-strength criterion (or the λci criterion) for vortex extraction is applied to the fluctuating portion of the computed velocity field, and the process of interaction of hairpin vortices and turbulent ejection- and sweep events is confirmed.