Time resolved measurements of droplet preferential concentration in homogeneous isotropic turbulence without mean flow
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Published version
Author(s)
Lian, Huan
Chang, XY
Hardalupas, Ioannis
Type
Journal Article
Abstract
An experimental investigation of the time-dependent spatial distribution of droplet concentration in a ‘box’ of stationary homogeneous and isotropic turbulence without mean flow was performed for polydispersed droplet clouds with a wide range of mean droplet diameters and droplet size distributions, characterized by a representative Stokes number, based on the droplet arithmetic diameter and the Kolmogorov timescale of the flow, varying between 0.2 and 6, and for turbulent Reynolds numbers of 98, 127, 147 and 235. A novel morphological tracking scheme was used to provide temporal tracking of droplet clusters according to cluster morphological features. The tracking scheme was based on Voronoï space tessellation, multivariate kernel density estimation and mean shift feature space tracking. The developed tracking scheme was used to establish the relationship between the morphological features of droplet clusters, i.e. number of clusters per unit area and cluster lengthscales, and the velocity of droplet clusters. The timescale of the droplet clusters increased with both the turbulent Reynolds number and the Stokes number, but its dependence was stronger on the turbulence level. In addition, the effect of filling factors of turbulent flows by turbulent structures on droplet clustering was discussed, which led to suggestions of potential flow control methods to mitigate droplet preferential concentration.
Date Issued
2019-02-04
Date Acceptance
2019-01-14
Citation
Physics of Fluids, 2019, 31 (2), pp.1-20
ISSN
1070-6631
Publisher
American Institute of Physics
Start Page
1
End Page
20
Journal / Book Title
Physics of Fluids
Volume
31
Issue
2
Copyright Statement
© 2019 The Authors. Published by AIP Publishing.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://aip.scitation.org/doi/10.1063/1.5063673
Grant Number
EP/E029515/1
Subjects
Science & Technology
Technology
Physical Sciences
Mechanics
Physics, Fluids & Plasmas
Physics
INERTIAL PARTICLES
SETTLING VELOCITY
Fluids & Plasmas
01 Mathematical Sciences
02 Physical Sciences
09 Engineering
Publication Status
Published
Article Number
025103
Date Publish Online
2019-02-04