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Shear effects on flow past a square cylinder at moderate reynolds numbers / Shuyang Cao in Journal of engineering mechanics, Vol. 138 N° 1 (Janvier 2012) 

Public ISBD [article]  in Journal of engineering mechanics > Vol. 138 N° 1 (Janvier 2012) . - pp.116- 123 Titre : Shear effects on flow past a square cylinder at moderate reynolds numbers Type de document : texte imprimé Auteurs : Shuyang Cao, Auteur ; Yaojun Ge, Auteur ; Yukio Tamura, Auteur Année de publication : 2012 Article en page(s) : pp.116- 123 Note générale : Mécanique appliquée Langues : Anglais (eng) Mots-clés : Aerodynamic  force  Direct  numerical  simulation  Large  eddy  simulation  Shear  parameter  Vortex  shedding  Wake  dynamics Résumé : Direct numerical simulation (DNS) and large eddy simulation (LES) with a dynamic Smagorinsky subgrid model are performed to investigate the flow past a square cylinder under the influence of velocity shear at the inlet at moderate Reynolds numbers ( R=150–1,000 ). The shear rate is expressed by a dimensionless shear parameter β , which is based on the velocity gradient, side length of the cylinder, and upstream velocity at the center plane of the cylinder. Shear parameter varies from 0 to 0.2 in this study. Several Reynolds numbers are considered to study the Reynolds number dependence and the Strouhal number were found to have no significant variation with the shear parameter. The peak frequency of drag coefficient fluctuation becomes identical with that of the lift force coefficient when β>0.1 . The vortices on the low-velocity side disappear in the far wake under the strong shear condition. The stagnation point moves to the high-velocity side and the movement increases with an increase in shear parameter. An interesting finding is that the lift force acts from the low-velocity to the high-velocity side, which is opposite to the case of a circular cylinder under the same inflow situation, whereas the drag force shows little variation with shear parameter. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000309 [article] Shear effects on flow past a square cylinder at moderate reynolds numbers [texte imprimé] / Shuyang Cao, Auteur ; Yaojun Ge, Auteur ; Yukio Tamura, Auteur . - 2012 . - pp.116- 123. Mécanique appliquée Langues : Anglais (eng) in Journal of engineering mechanics > Vol. 138 N° 1 (Janvier 2012) . - pp.116- 123 Mots-clés : Aerodynamic  force  Direct  numerical  simulation  Large  eddy  simulation  Shear  parameter  Vortex  shedding  Wake  dynamics Résumé : Direct numerical simulation (DNS) and large eddy simulation (LES) with a dynamic Smagorinsky subgrid model are performed to investigate the flow past a square cylinder under the influence of velocity shear at the inlet at moderate Reynolds numbers ( R=150–1,000 ). The shear rate is expressed by a dimensionless shear parameter β , which is based on the velocity gradient, side length of the cylinder, and upstream velocity at the center plane of the cylinder. Shear parameter varies from 0 to 0.2 in this study. Several Reynolds numbers are considered to study the Reynolds number dependence and the Strouhal number were found to have no significant variation with the shear parameter. The peak frequency of drag coefficient fluctuation becomes identical with that of the lift force coefficient when β>0.1 . The vortices on the low-velocity side disappear in the far wake under the strong shear condition. The stagnation point moves to the high-velocity side and the movement increases with an increase in shear parameter. An interesting finding is that the lift force acts from the low-velocity to the high-velocity side, which is opposite to the case of a circular cylinder under the same inflow situation, whereas the drag force shows little variation with shear parameter. ISSN : 0733-9399 En ligne : http://ascelibrary.org/doi/abs/10.1061/%28ASCE%29EM.1943-7889.0000309