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Title: Turbulent jets with off-source heating

Abstract

Motivated by anomalous entrainment behaviour in cumulus clouds, Bhatet al.(Exp. Fluids, vol. 7, 1989, pp. 99–102) pioneered a laboratory experiment to study turbulent jets subjected to a volumetric heating away from the momentum source. The study concluded that the use of a constant entrainment coefficient was insufficient for the flow, and that the results did not confirm the analysis of Hunt (Recent Research Advances in the Fluid Mechanics of Turbulent Jets and Plumes, 1994, pp. 309–334, Kluwer Academic), which suggested that an increase in relative turbulent transport of streamwise momentum could lead to a decrease in entrainment. The present paper re-evaluates theoretical aspects of both studies, and includes a decomposition of the factors contributing to entrainment. The reworked analysis is then used to examine three-dimensional numerical simulations of turbulent jets with off-source heating. The data are consistent with previous work, but give deeper insight not easily obtainable through experiment. Specifically, direct measurement of flux integrals shows that previous inference from experimental measurements of centreline velocity and profile widths under the assumption of self-similarity can lead to underestimation of the mass flux by over 50 % in some cases. Radial profiles of temperature, radial velocity and turbulent correlations show significant departures from self-similarity.more » The flux measurements show that there is actually an increase in the entrainment coefficient with heating, and that it is locally enhanced by positive forcing and decreased by an increase in turbulent transport of streamwise momentum, thereby confirming the essence of the original proposal of Hunt.« less

Authors:
ORCiD logo; ; ;
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory-National Energy Research Scientific Computing Center
Sponsoring Org.:
USDOE
OSTI Identifier:
1479472
Resource Type:
Journal Article
Journal Name:
Journal of Fluid Mechanics
Additional Journal Information:
Journal Volume: 824; Journal ID: ISSN 0022-1120
Publisher:
Cambridge University Press
Country of Publication:
United States
Language:
English

Citation Formats

Aspden, A. J., Nikiforakis, N., Bell, J. B., and Dalziel, Stuart B. Turbulent jets with off-source heating. United States: N. p., 2017. Web. doi:10.1017/jfm.2017.272.
Aspden, A. J., Nikiforakis, N., Bell, J. B., & Dalziel, Stuart B. Turbulent jets with off-source heating. United States. doi:10.1017/jfm.2017.272.
Aspden, A. J., Nikiforakis, N., Bell, J. B., and Dalziel, Stuart B. Tue . "Turbulent jets with off-source heating". United States. doi:10.1017/jfm.2017.272.
@article{osti_1479472,
title = {Turbulent jets with off-source heating},
author = {Aspden, A. J. and Nikiforakis, N. and Bell, J. B. and Dalziel, Stuart B.},
abstractNote = {Motivated by anomalous entrainment behaviour in cumulus clouds, Bhatet al.(Exp. Fluids, vol. 7, 1989, pp. 99–102) pioneered a laboratory experiment to study turbulent jets subjected to a volumetric heating away from the momentum source. The study concluded that the use of a constant entrainment coefficient was insufficient for the flow, and that the results did not confirm the analysis of Hunt (Recent Research Advances in the Fluid Mechanics of Turbulent Jets and Plumes, 1994, pp. 309–334, Kluwer Academic), which suggested that an increase in relative turbulent transport of streamwise momentum could lead to a decrease in entrainment. The present paper re-evaluates theoretical aspects of both studies, and includes a decomposition of the factors contributing to entrainment. The reworked analysis is then used to examine three-dimensional numerical simulations of turbulent jets with off-source heating. The data are consistent with previous work, but give deeper insight not easily obtainable through experiment. Specifically, direct measurement of flux integrals shows that previous inference from experimental measurements of centreline velocity and profile widths under the assumption of self-similarity can lead to underestimation of the mass flux by over 50 % in some cases. Radial profiles of temperature, radial velocity and turbulent correlations show significant departures from self-similarity. The flux measurements show that there is actually an increase in the entrainment coefficient with heating, and that it is locally enhanced by positive forcing and decreased by an increase in turbulent transport of streamwise momentum, thereby confirming the essence of the original proposal of Hunt.},
doi = {10.1017/jfm.2017.272},
journal = {Journal of Fluid Mechanics},
issn = {0022-1120},
number = ,
volume = 824,
place = {United States},
year = {2017},
month = {7}
}

Works referenced in this record:

A volumetrically heated jet: large-eddy structure and entrainment characteristics
journal, October 1996


Energy-consistent entrainment relations for jets and plumes
journal, October 2015

  • van Reeuwijk, Maarten; Craske, John
  • Journal of Fluid Mechanics, Vol. 782
  • DOI: 10.1017/jfm.2015.534

Velocity measurements in a high-Reynolds-number, momentum-conserving, axisymmetric, turbulent jet
journal, January 1994

  • Hussein, Hussein J.; Capp, Steven P.; George, William K.
  • Journal of Fluid Mechanics, Vol. 258
  • DOI: 10.1017/S002211209400323X

An experimental study of a jet with local buoyancy enhancement
journal, September 1995


Analysis of implicit LES methods
journal, January 2008

  • Aspden, Andrew; Nikiforakis, Nikos; Dalziel, Stuart
  • Communications in Applied Mathematics and Computational Science, Vol. 3, Issue 1
  • DOI: 10.2140/camcos.2008.3.103

Direct numerical simulation of a turbulent axisymmetric jet with buoyancy induced acceleration
journal, January 2005

  • Agrawal, Amit; Boersma, B. J.; Prasad, Ajay K.
  • Flow, Turbulence and Combustion, Vol. 73, Issue 3-4
  • DOI: 10.1007/s10494-005-8051-1

A Conservative Adaptive Projection Method for the Variable Density Incompressible Navier–Stokes Equations
journal, May 1998

  • Almgren, Ann S.; Bell, John B.; Colella, Phillip
  • Journal of Computational Physics, Vol. 142, Issue 1
  • DOI: 10.1006/jcph.1998.5890

Evolution of a turbulent jet subjected to volumetric heating
journal, January 1999


A new method of producing local enhancement of buoyancy in liquid flows
journal, November 1989

  • Bhat, G. S.; Narasimha, R.; Arakeri, V. H.
  • Experiments in Fluids, Vol. 7, Issue 2
  • DOI: 10.1007/BF00207301

Experiments on a plume with off-source heating: Implications for cloud fluid dynamics
journal, June 1999

  • Venkatakrishnan, L.; Bhat, G. S.; Narasimha, R.
  • Journal of Geophysical Research: Atmospheres, Vol. 104, Issue D12
  • DOI: 10.1029/1999JD900034

The effect of sudden source buoyancy flux increases on turbulent plumes
journal, September 2009


Turbulent entrainment in jets with arbitrary buoyancy
journal, January 1999


An entraining jet model for cumulo-nimbus updraughts
journal, January 1962


Velocity and temperature measurements in an axisymmetric turbulent jet with cloud-like off-source heating
journal, March 2004


Generalised unsteady plume theory
journal, March 2016

  • Craske, John; van Reeuwijk, Maarten
  • Journal of Fluid Mechanics, Vol. 792
  • DOI: 10.1017/jfm.2016.72

Lazy plumes
journal, June 2005


BURNING THERMALS IN TYPE Ia SUPERNOVAE
journal, August 2011


Continuous convection from an isolated source of heat
journal, April 1955

  • Priestley, C. H. B.; Ball, F. K.
  • Quarterly Journal of the Royal Meteorological Society, Vol. 81, Issue 348
  • DOI: 10.1002/qj.49708134803