The interaction between vortical structures and turbulent events in the wall region of a turbulent channel fow is investigated numerically. The system of the incompressible Navier-Stokes equations is integrated by using a mixed spectral fnite-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 fuctuating portion of the computed velocity feld, and the process of interaction of hairpin vortices and turbulent ejection- and sweep events is confrmed.
Turbulent events in a wall-bounded turbulent flow
Alfonsi G.
;Primavera L.
2012-01-01
Abstract
The interaction between vortical structures and turbulent events in the wall region of a turbulent channel fow is investigated numerically. The system of the incompressible Navier-Stokes equations is integrated by using a mixed spectral fnite-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 fuctuating portion of the computed velocity feld, and the process of interaction of hairpin vortices and turbulent ejection- and sweep events is confrmed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
