Conference Proceedings

Characteristics of the entrainment velocity in a developing wake

J Philip, I Bermejo-Moreno, D Chung, I MARUSIC

International Symposium on Turbulence and Shear Flow Phenomena | Published : 2015

Abstract

Characteristics of enstrophy generation and entrainment velocity at the turbulent non-turbulent interface of a temporally evolving wake are studied using Direct Numerical Simulations (DNS), starting from the time instance when the instabilities develop to a fully turbulent state. Results reveal the dominant role of viscous effects compared to the production of enstrophy at the interface at all time instances, although Kolmogorov scaling is found not to apply. The entrainment velocity vn is dominated by a balance of viscous diffusion and dissipation of enstrophy, and the pdf of vn shows large positive tails in fully turbulent regimes which are absent during the initial development of the wake..

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