Journal article

Kinematics of local entrainment and detrainment in a turbulent jet

Dhiren Mistry, Jimmy Philip, James R Dawson

Journal of Fluid Mechanics | Cambridge University Press (CUP) | Published : 2019

Abstract

In this paper we investigate the continuous, local exchange of fluid elements as they are entrained and detrained across the turbulent/non-turbulent interface (TNTI) in a high Reynolds number axisymmetric jet. To elucidate characteristic kinematic features of local entrainment and detrainment processes, simultaneous high-speed particle image velocimetry and planar laser-induced fluorescence measurements were undertaken. Using an interface-tracking technique, we evaluate and analyse the conditional dependence of local entrainment velocity in a frame of reference moving with the TNTI in terms of the interface geometry and the local flow field. We find that the local entrainment velocity is int..

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University of Melbourne Researchers

Grants

Awarded by UK Engineering and Physical Sciences Research Council


Awarded by Norwegian Research Council


Funding Acknowledgements

The authors wish to thank the UK Engineering and Physical Sciences Research Council (research grant no. EP/I005897/1), the Norwegian Research Council (research grant no. 244386) and the Australian Research Council for the financial support of this work. The visit of D.M. to the University of Melbourne was supported by the David Crighton Fellowship from the Department of Applied Mathematics and Theoretical Physics, Cambridge.