矩形ダクト流における乱流パフの大域的対称性の破れ

抄録

In this study, localized structures appearing in transition to turbulence are numerically investigated in rectangularduct flow. It is observed that streamwise localized turbulent puffs are skewed for the specific values of the Reynolds number and the aspect ratio. The organized cross flow arises in the averaged flow field as a consequence of the symmetry breaking of turbulent puffs with respect to the duct midplane for the critical aspect ratio. The streamwise vorticity fields are examined to find out that there emerges clear skew in the arrangement of vortical structures if the aspect ratio exceeds the critical value.