Small scale entrainment characteristics in high Reynolds number jets and wakes

The characteristics of the turbulent/non-turbulent interface (TNTI) that occurs at the edges of free shear layers such as mixing layers, jets and wakes, and also in boundary layers, is analysed through new high resolution direct numerical simulations (DNS) of planar turbulent jets and wakes (PJET and PWAKE). It is shown that provided the Reynolds number is above a certain threshold Re-lambda > 200, thickness of the viscous dominated sublayer, known as viscous superlayer (VSL - delta(nu)) as that of the entire turbulent/non-turbulent interface layer (TNTI - delta(omega)) both scale with the Kolmogorov micro-scale. The differences and similarities between the TNTIs from jets and wakes, as well how these affect the dynamics of the nearby vorticity, is discussed.