Abstract
Two different mathematical methods of implementing a detailed kinetic soot model have been employed in this work. The theoretical description of the soot modeling employed in this work is divided into three parts. Initially a detailed kinetic soot model is described from a chemistry and physics perspective. The soot model is then elaborated into mathematical form, starting with the formulation of the method of moments. Later on a thorough description of the sectional mathematical formulation of the detailed kinetic soot model is given. The sectional method is a new addition to the toolbox developed and used by the kinetic workgroup at Lund University.
The sectional method and the moment method are compared, with the focus of doing a theoretical validation of the sectional method. Where discrepancies between the models exist, due to choices of approximations and discretizations, these are investigated and explained. The validation is carried out in the framework of a 0dimensional code usually used for describing the process of ignition in perfectly stirred combustion reactors. A 0dimensional reactor tool is also used, in which precalculated or premeasured chemistry profiles are read in. Based on the readin profiles soot formation is calculated. Features as well as limitations of the sectional method are investigated.
The sectional method is also validated using experimental data. A laminar premixed flame is modeled and the calculated profiles of the soot particle size distribution function are compared to experimentally measured distributions. Comparisons are made for different flames with different temperatures. An investigation on how the sectional method performs with another well known soot model is also performed.
The moment method and the sectional method are both applied in different turbulent nonpremixed combustion cases. In most of the work the soot models are used within the general turbulent combustion modeling approach called the flamelet model. Turbulent nonpremixed combustion is also modeled using a stochastic reactor model.
Turbulent diffusion flames are simulated using the flamelet model. The flamelet model describes the turbulent flame as an ensemble of 1dimensional laminar diffusion flames, socalled flamelets. The interaction between flowfield and chemical reactions is described, while decoupling the actual calculations of chemistry and flowfield. Both the moment method and the sectional method have been applied within the flamelet model to study turbulent freely propagating diffusion flames. By applying the sectional method in a turbulent flame, spatially detailed information on the evolution of the soot particle size distribution was obtained. This is novel and has taken the study of soot formation and specifically the study of the evolution of the soot particle size distribution into a new area. The moment method in combination with the flamelet model was also used to investigate diesel engine combustion.
A stochastic reactor tool is used to model carbon black (i.e. soot) formation in a carbon black reactor. This tool is a 0dimensional model, assuming spatial homogeneity can be replaced by statistical homogeneity.
The sectional method and the moment method are compared, with the focus of doing a theoretical validation of the sectional method. Where discrepancies between the models exist, due to choices of approximations and discretizations, these are investigated and explained. The validation is carried out in the framework of a 0dimensional code usually used for describing the process of ignition in perfectly stirred combustion reactors. A 0dimensional reactor tool is also used, in which precalculated or premeasured chemistry profiles are read in. Based on the readin profiles soot formation is calculated. Features as well as limitations of the sectional method are investigated.
The sectional method is also validated using experimental data. A laminar premixed flame is modeled and the calculated profiles of the soot particle size distribution function are compared to experimentally measured distributions. Comparisons are made for different flames with different temperatures. An investigation on how the sectional method performs with another well known soot model is also performed.
The moment method and the sectional method are both applied in different turbulent nonpremixed combustion cases. In most of the work the soot models are used within the general turbulent combustion modeling approach called the flamelet model. Turbulent nonpremixed combustion is also modeled using a stochastic reactor model.
Turbulent diffusion flames are simulated using the flamelet model. The flamelet model describes the turbulent flame as an ensemble of 1dimensional laminar diffusion flames, socalled flamelets. The interaction between flowfield and chemical reactions is described, while decoupling the actual calculations of chemistry and flowfield. Both the moment method and the sectional method have been applied within the flamelet model to study turbulent freely propagating diffusion flames. By applying the sectional method in a turbulent flame, spatially detailed information on the evolution of the soot particle size distribution was obtained. This is novel and has taken the study of soot formation and specifically the study of the evolution of the soot particle size distribution into a new area. The moment method in combination with the flamelet model was also used to investigate diesel engine combustion.
A stochastic reactor tool is used to model carbon black (i.e. soot) formation in a carbon black reactor. This tool is a 0dimensional model, assuming spatial homogeneity can be replaced by statistical homogeneity.
Original language  English 

Qualification  Doctor 
Awarding Institution 

Supervisors/Advisors 

Award date  2006 Nov 23 
Publication status  Published  2006 
Bibliographical note
Defence detailsDate: 20061123
Time: 10:15
Place: Room F, Department of Physics, "Fysicum", Professorsgatan 1, Lund Institute of Technology
External reviewer(s)
Name: Pratsinis, Sotiris
Title: Professor
Affiliation: Swiss Federal Institute of Technology

Subject classification (UKÄ)
 Atom and Molecular Physics and Optics
Keywords
 Fysik
 flamelet model
 Physics
 particle distribution
 soot
 moment method
 sectional method
 particle size distribution function