Budgets of flame-conditioned second-order turbulence statistics in low and high Karlovitz number turbulent premixed jet flames
Budgets of flame-conditioned second-order turbulence statistics in low and high Karlovitz number turbulent premixed jet flames
Small-scale heat release in low Karlovitz number turbulent premixed combustion significantly affects large-scale turbulence dynamics through nonlinear interactions occurring within the flame structure. These interactions result in flame-local changes to the alignment of the Reynolds stress and scalar fluxes with the mean gradients that lead to failure of commonly-used Boussinesq and gradient diffusion-type turbulence models. In this work, flame-conditioned second-order turbulence statistics, that is, velocity correlations and cross-correlations conditioned on a reaction progress variable, are computed following the concept of Conditional Moment Closure (CMC). By conditioning on a local flame coordinate, this statistical basis removes effects of flame motion that are responsible for the observed statistical misalignment at low Karlovitz number. The turbulent kinetic energy (TKE) is evaluated using data from Direct Numerical Simulation (DNS) of spatially-evolving turbulent premixed jet flames at low and high Karlovitz numbers. The evolution equations are derived, and budgets of these equations are computed in the two Karlovitz number cases. In analysis of these budgets, more precise mechanisms of interaction between combustion heat release and turbulence are suggested, and implications for modeling efforts are discussed.
Conditional velocity, Direct numerical simulation, Turbulence statistics, Turbulent premixed combustion
MacArt, Jonathan F.
1384a548-486e-4fae-9d5c-4177b0ed7825
Grenga, Temistocle
be0eba30-74b5-4134-87e7-3a2d6dd3836f
Mueller, Michael E.
de069534-2aa2-4382-a380-0f3fdbfc6526
2018
MacArt, Jonathan F.
1384a548-486e-4fae-9d5c-4177b0ed7825
Grenga, Temistocle
be0eba30-74b5-4134-87e7-3a2d6dd3836f
Mueller, Michael E.
de069534-2aa2-4382-a380-0f3fdbfc6526
MacArt, Jonathan F., Grenga, Temistocle and Mueller, Michael E.
(2018)
Budgets of flame-conditioned second-order turbulence statistics in low and high Karlovitz number turbulent premixed jet flames.
2018 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2018, , State College, United States.
04 - 07 Mar 2018.
Record type:
Conference or Workshop Item
(Paper)
Abstract
Small-scale heat release in low Karlovitz number turbulent premixed combustion significantly affects large-scale turbulence dynamics through nonlinear interactions occurring within the flame structure. These interactions result in flame-local changes to the alignment of the Reynolds stress and scalar fluxes with the mean gradients that lead to failure of commonly-used Boussinesq and gradient diffusion-type turbulence models. In this work, flame-conditioned second-order turbulence statistics, that is, velocity correlations and cross-correlations conditioned on a reaction progress variable, are computed following the concept of Conditional Moment Closure (CMC). By conditioning on a local flame coordinate, this statistical basis removes effects of flame motion that are responsible for the observed statistical misalignment at low Karlovitz number. The turbulent kinetic energy (TKE) is evaluated using data from Direct Numerical Simulation (DNS) of spatially-evolving turbulent premixed jet flames at low and high Karlovitz numbers. The evolution equations are derived, and budgets of these equations are computed in the two Karlovitz number cases. In analysis of these budgets, more precise mechanisms of interaction between combustion heat release and turbulence are suggested, and implications for modeling efforts are discussed.
This record has no associated files available for download.
More information
Published date: 2018
Additional Information:
Publisher Copyright:
© 2018 Western States Section/Combustion Institute. All rights reserved.
Venue - Dates:
2018 Spring Technical Meeting of the Eastern States Section of the Combustion Institute, ESSCI 2018, , State College, United States, 2018-03-04 - 2018-03-07
Keywords:
Conditional velocity, Direct numerical simulation, Turbulence statistics, Turbulent premixed combustion
Identifiers
Local EPrints ID: 480922
URI: http://eprints.soton.ac.uk/id/eprint/480922
PURE UUID: ae1951cc-075b-48fc-b8d8-0db84aa765e3
Catalogue record
Date deposited: 10 Aug 2023 16:59
Last modified: 11 Aug 2023 02:02
Export record
Contributors
Author:
Jonathan F. MacArt
Author:
Temistocle Grenga
Author:
Michael E. Mueller
Download statistics
Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.
View more statistics