Abstract
This thesis analyses turbulent reacting flows with emphasis on the interaction between the turbulence and the chemistry. First, the fundamental equations which govern laminar and turbulent reacting flows are presented. Three alternatives for representing the chemistry in turbulent combustion are studied. The simplest alternative is to assume fast chemistry. Detailed reaction mechanisms give a more accurate description of the chemistry, but are computationally expensive to use. The intrinsic low-dimensional manifold (ILDM) method for reducing the chemistry is an approach for obtaining an accurate representation of the chemistry at less computational effort. In order to be of practical use for turbulent flows, a statistical treatment of the governing equations is necessary. The outcome of such a treatment is either a set of transport equations for the probability density function (pdf). Regardless of which method is used, unknown terms that must be modeled, appear. The major difficulty in the moment-transport method is the closure of the mean chemical reaction term. Two methods to obtain this have been tested. One is based on viewing the smallest eddies of the turbulence as homogeneous reactors. This allows for a detailed treatment of the chemistry. The other approach assumes a particular shape for the pdf. When
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Citation Formats
Gran, I R.
Mathematical modeling and numerical simulation of chemical kinetics in turbulent combustion.
Norway: N. p.,
1994.
Web.
Gran, I R.
Mathematical modeling and numerical simulation of chemical kinetics in turbulent combustion.
Norway.
Gran, I R.
1994.
"Mathematical modeling and numerical simulation of chemical kinetics in turbulent combustion."
Norway.
@misc{etde_10105846,
title = {Mathematical modeling and numerical simulation of chemical kinetics in turbulent combustion}
author = {Gran, I R}
abstractNote = {This thesis analyses turbulent reacting flows with emphasis on the interaction between the turbulence and the chemistry. First, the fundamental equations which govern laminar and turbulent reacting flows are presented. Three alternatives for representing the chemistry in turbulent combustion are studied. The simplest alternative is to assume fast chemistry. Detailed reaction mechanisms give a more accurate description of the chemistry, but are computationally expensive to use. The intrinsic low-dimensional manifold (ILDM) method for reducing the chemistry is an approach for obtaining an accurate representation of the chemistry at less computational effort. In order to be of practical use for turbulent flows, a statistical treatment of the governing equations is necessary. The outcome of such a treatment is either a set of transport equations for the probability density function (pdf). Regardless of which method is used, unknown terms that must be modeled, appear. The major difficulty in the moment-transport method is the closure of the mean chemical reaction term. Two methods to obtain this have been tested. One is based on viewing the smallest eddies of the turbulence as homogeneous reactors. This allows for a detailed treatment of the chemistry. The other approach assumes a particular shape for the pdf. When the transport equation for the pdf is solved, the effects of chemical reaction appear in closed form. The main difficulty in the pdf-transport method is the modeling of the effects of molecular diffusion on the pdf. Some kind of reduced chemistry is required when using the pdf-transport method. The ILDM method is ideally suited for this. 153 refs., 94 figs., 6 tabs.}
place = {Norway}
year = {1994}
month = {May}
}
title = {Mathematical modeling and numerical simulation of chemical kinetics in turbulent combustion}
author = {Gran, I R}
abstractNote = {This thesis analyses turbulent reacting flows with emphasis on the interaction between the turbulence and the chemistry. First, the fundamental equations which govern laminar and turbulent reacting flows are presented. Three alternatives for representing the chemistry in turbulent combustion are studied. The simplest alternative is to assume fast chemistry. Detailed reaction mechanisms give a more accurate description of the chemistry, but are computationally expensive to use. The intrinsic low-dimensional manifold (ILDM) method for reducing the chemistry is an approach for obtaining an accurate representation of the chemistry at less computational effort. In order to be of practical use for turbulent flows, a statistical treatment of the governing equations is necessary. The outcome of such a treatment is either a set of transport equations for the probability density function (pdf). Regardless of which method is used, unknown terms that must be modeled, appear. The major difficulty in the moment-transport method is the closure of the mean chemical reaction term. Two methods to obtain this have been tested. One is based on viewing the smallest eddies of the turbulence as homogeneous reactors. This allows for a detailed treatment of the chemistry. The other approach assumes a particular shape for the pdf. When the transport equation for the pdf is solved, the effects of chemical reaction appear in closed form. The main difficulty in the pdf-transport method is the modeling of the effects of molecular diffusion on the pdf. Some kind of reduced chemistry is required when using the pdf-transport method. The ILDM method is ideally suited for this. 153 refs., 94 figs., 6 tabs.}
place = {Norway}
year = {1994}
month = {May}
}