Geometrical aspects of turbulent/non-turbulent interfaces with and without mean shear

摘要: The geometry of turbulent/non-turbulent interfaces (TNTIs) arising from flows with and without mean shear is investigated using direct numerical simulations turbulent planar jets (PJET) free turbulence (SFT), respectively, Taylor Reynolds number about Reλ≈100. In both flows, the TNTI preferentially aligned tangent to displaying convex, where fluid nearby tends have a stronger enstrophy, more frequently than concave shapes. different flow configurations are reflected in orientations respect direction (and its normal). While interface orientation PJET has an influence on velocity field near enstrophy production sublayer, there no particular discernible dependence SFT. Finally, intense vorticity structures or “worms,” which possibly associated “nibbling” entrainment mechanism, ...