Micro mixing time in the Eddy Dissipation Concept

Lars Kjäldman, Anders Brink (Corresponding Author), Mikko Hupa

Research output: Contribution to journalArticleScientificpeer-review

22 Citations (Scopus)

Abstract

The turbulent micro mixing in the Eddy Dissipation Concept (EDC) has been investigated. The EDC is a model for turbulence-chemistry interaction modeling that allows for the use of multi-step reactions. The EDC was originally developed assuming that the reaction kinetics is fast compared to the turbulent mixing. With a more detailed description of the chemistry the interaction between turbulence and chemistry becomes more complex which may call for a revision of the model. Three ways to estimate the turbulent mixing times have been investigated. The first is the time scale proposed in the EDC, i.e., the lime scale related to the Kolinogorov time scale. The second is a time scale based on the geometrical mean of the Kolinogorov time scale and the time scale given by k/ϵ. The third time scale is the time scale given by 4k/epsiv;, The fuel chemistry was modeled with a three-step simplified mechanism A separate model based on calculations with a comprehensive reaction mechanism was used for estimating the chemical time scale at which extinction occurs. In the study a natural gas-fired sudden expansion reactor was modeled. The use of the Kolmogorov related time scale resulted in an overestimation of the extinction effects, whereas best result was obtained when the mixing time was modeled with the time scale given by 4kϵ.

Original languageEnglish
Pages (from-to)207 - 227
Number of pages21
JournalCombustion Science and Technology
Volume154
Issue number1
DOIs
Publication statusPublished - 2000
MoE publication typeA1 Journal article-refereed

Fingerprint

dissipation
vortices
Turbulence
chemistry
Reaction kinetics
Lime
turbulent mixing
Natural gas
extinction
turbulence
natural gas
calcium oxides
reaction kinetics
estimating
reactors
interactions
expansion
estimates

Cite this

Kjäldman, Lars ; Brink, Anders ; Hupa, Mikko. / Micro mixing time in the Eddy Dissipation Concept. In: Combustion Science and Technology. 2000 ; Vol. 154, No. 1. pp. 207 - 227.
@article{f93161a0e96047c6aaef4fc7e70ffa41,
title = "Micro mixing time in the Eddy Dissipation Concept",
abstract = "The turbulent micro mixing in the Eddy Dissipation Concept (EDC) has been investigated. The EDC is a model for turbulence-chemistry interaction modeling that allows for the use of multi-step reactions. The EDC was originally developed assuming that the reaction kinetics is fast compared to the turbulent mixing. With a more detailed description of the chemistry the interaction between turbulence and chemistry becomes more complex which may call for a revision of the model. Three ways to estimate the turbulent mixing times have been investigated. The first is the time scale proposed in the EDC, i.e., the lime scale related to the Kolinogorov time scale. The second is a time scale based on the geometrical mean of the Kolinogorov time scale and the time scale given by k/ϵ. The third time scale is the time scale given by 4k/epsiv;, The fuel chemistry was modeled with a three-step simplified mechanism A separate model based on calculations with a comprehensive reaction mechanism was used for estimating the chemical time scale at which extinction occurs. In the study a natural gas-fired sudden expansion reactor was modeled. The use of the Kolmogorov related time scale resulted in an overestimation of the extinction effects, whereas best result was obtained when the mixing time was modeled with the time scale given by 4kϵ.",
author = "Lars Kj{\"a}ldman and Anders Brink and Mikko Hupa",
year = "2000",
doi = "10.1080/00102200008947277",
language = "English",
volume = "154",
pages = "207 -- 227",
journal = "Combustion Science and Technology",
issn = "0010-2202",
publisher = "Taylor & Francis",
number = "1",

}

Micro mixing time in the Eddy Dissipation Concept. / Kjäldman, Lars; Brink, Anders (Corresponding Author); Hupa, Mikko.

In: Combustion Science and Technology, Vol. 154, No. 1, 2000, p. 207 - 227.

Research output: Contribution to journalArticleScientificpeer-review

TY - JOUR

T1 - Micro mixing time in the Eddy Dissipation Concept

AU - Kjäldman, Lars

AU - Brink, Anders

AU - Hupa, Mikko

PY - 2000

Y1 - 2000

N2 - The turbulent micro mixing in the Eddy Dissipation Concept (EDC) has been investigated. The EDC is a model for turbulence-chemistry interaction modeling that allows for the use of multi-step reactions. The EDC was originally developed assuming that the reaction kinetics is fast compared to the turbulent mixing. With a more detailed description of the chemistry the interaction between turbulence and chemistry becomes more complex which may call for a revision of the model. Three ways to estimate the turbulent mixing times have been investigated. The first is the time scale proposed in the EDC, i.e., the lime scale related to the Kolinogorov time scale. The second is a time scale based on the geometrical mean of the Kolinogorov time scale and the time scale given by k/ϵ. The third time scale is the time scale given by 4k/epsiv;, The fuel chemistry was modeled with a three-step simplified mechanism A separate model based on calculations with a comprehensive reaction mechanism was used for estimating the chemical time scale at which extinction occurs. In the study a natural gas-fired sudden expansion reactor was modeled. The use of the Kolmogorov related time scale resulted in an overestimation of the extinction effects, whereas best result was obtained when the mixing time was modeled with the time scale given by 4kϵ.

AB - The turbulent micro mixing in the Eddy Dissipation Concept (EDC) has been investigated. The EDC is a model for turbulence-chemistry interaction modeling that allows for the use of multi-step reactions. The EDC was originally developed assuming that the reaction kinetics is fast compared to the turbulent mixing. With a more detailed description of the chemistry the interaction between turbulence and chemistry becomes more complex which may call for a revision of the model. Three ways to estimate the turbulent mixing times have been investigated. The first is the time scale proposed in the EDC, i.e., the lime scale related to the Kolinogorov time scale. The second is a time scale based on the geometrical mean of the Kolinogorov time scale and the time scale given by k/ϵ. The third time scale is the time scale given by 4k/epsiv;, The fuel chemistry was modeled with a three-step simplified mechanism A separate model based on calculations with a comprehensive reaction mechanism was used for estimating the chemical time scale at which extinction occurs. In the study a natural gas-fired sudden expansion reactor was modeled. The use of the Kolmogorov related time scale resulted in an overestimation of the extinction effects, whereas best result was obtained when the mixing time was modeled with the time scale given by 4kϵ.

U2 - 10.1080/00102200008947277

DO - 10.1080/00102200008947277

M3 - Article

VL - 154

SP - 207

EP - 227

JO - Combustion Science and Technology

JF - Combustion Science and Technology

SN - 0010-2202

IS - 1

ER -