Imperial College London
Alternate

DrHenryBurridge

Faculty of Engineering, Department of Civil and Environmental Engineering

Senior Lecturer
 
 
 
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Contact

 

+44 (0)20 7594 5201h.burridge Website

 
 
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Assistant

 

Miss Rebecca Naessens +44 (0)20 7594 5990

 
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Location

 

328ASkempton BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Huang:2023:10.1017/jfm.2023.947,
author = {Huang, J and van, Reeuwijk M and Burridge, H},
doi = {10.1017/jfm.2023.947},
journal = {Journal of Fluid Mechanics},
title = {Local entrainment across a TNTI and TTI in a turbulent forced fountain},
url = {http://dx.doi.org/10.1017/jfm.2023.947},
volume = {977},
year = {2023}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Local instantaneous exchanges of volume, momentum and buoyancy across turbulent/non-turbulent interfaces (TNTIs) and turbulent/turbulent interfaces (TTIs) are studied using data from direct numerical simulations of a turbulent forced fountain. We apply a novel algorithm that enables independent calculation of the instantaneous local entrainment and detrainment fluxes, and therefore, for the first time, the entrainment and detrainment coefficients according to the fountain model (Bloomfield & Kerr, J. Fluid Mech., vol. 424, 2000, pp. 197–216) are determined explicitly. Across the interface between the fountain and the ambient fluid, which is a TNTI, only volume entrainment occurs, and it is well predicted by the fountain model. Across the interface between the rising upflow and falling downflow within the fountain, which is a TTI, both entrainment and detrainment of volume, momentum and buoyancy occur – with the magnitude of both entrainment and detrainment typically being large compared with the net for all exchanges. However, the model seems to be unable to capture the momentum exchanges due to its ignorance of the pressure. We find that each conditional entrainment and detrainment rate, of volume, momentum and buoyancy, can be described accurately by Gaussian profiles, while the net exchange that is the superposition of the entrainment and detrainment cannot. Moreover, the entrainment exchange rate has its maximum closer to the fountain centreline than that of detrainment, explaining the tendency for net entrainment closer to the fountain centreline and net detrainment further away.
AU  - Huang,J
AU  - van,Reeuwijk M
AU  - Burridge,H
DO  - 10.1017/jfm.2023.947
PY  - 2023///
SN  - 0022-1120
TI  - Local entrainment across a TNTI and TTI in a turbulent forced fountain
T2  - Journal of Fluid Mechanics
UR  - http://dx.doi.org/10.1017/jfm.2023.947
UR  - https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/local-entrainment-across-a-tnti-and-a-tti-in-a-turbulent-forced-fountain/D40C28D4F4C8D66BEAF0F28309F34BD4
UR  - http://hdl.handle.net/10044/1/107746
VL  - 977
ER  -
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