Direct numerical simulation of statistically stationary and homogeneous shear turbulence and its relation to other shear flows


Autoria(s): Atshusi, Sekimoto; Siwei, Dong; Jiménez Sendín, Javier
Data(s)

01/03/2016

31/12/1969

Resumo

Statistically stationary and homogeneous shear turbulence (SS-HST) is investigated by means of a new direct numerical simulation code, spectral in the two horizontal directions and compact-finite-differences in the direction of the shear. No remeshing is used to impose the shear-periodic boundary condition. The influence of the geometry of the computational box is explored. Since HST has no characteristic outer length scale and tends to fill the computational domain, long-term simulations of HST are “minimal” in the sense of containing on average only a few large-scale structures. It is found that the main limit is the spanwise box width, Lz, which sets the length and velocity scales of the turbulence, and that the two other box dimensions should be sufficiently large (Lx ≳ 2Lz, Ly ≳ Lz) to prevent other directions to be constrained as well. It is also found that very long boxes, Lx ≳ 2Ly, couple with the passing period of the shear-periodic boundary condition, and develop strong unphysical linearized bursts. Within those limits, the flow shows interesting similarities and differences with other shear flows, and in particular with the logarithmic layer of wall-bounded turbulence. They are explored in some detail. They include a self-sustaining process for large-scale streaks and quasi-periodic bursting. The bursting time scale is approximately universal, ∼20S−1, and the availability of two different bursting systems allows the growth of the bursts to be related with some confidence to the shearing of initially isotropic turbulence. It is concluded that SS-HST, conducted within the proper computational parameters, is a very promising system to study shear turbulence in general.

Formato

application/pdf

Identificador

http://oa.upm.es/40282/

Idioma(s)

eng

Publicador

E.T.S. de Ingeniería Aeronáutica y del Espacio (UPM)

Relação

http://oa.upm.es/40282/1/INVE_MEM_2016219805.pdf

http://scitation.aip.org/content/aip/journal/pof2/28/3/10.1063/1.4942496

info:eu-repo/semantics/altIdentifier/doi/http://dx.doi.org/10.1063/1.4942496

Direitos

http://creativecommons.org/licenses/by-nc-nd/3.0/es/

info:eu-repo/semantics/embargoedAccess

Fonte

Physics of Fluids, ISSN 1089-7666, 2016-03-01, Vol. 28, No. 3

Palavras-Chave #Aeronáutica
Tipo

info:eu-repo/semantics/article

Artículo

PeerReviewed