Abstract
The soot particle size distribution was studied via numerical simulation under diesel like engine conditions using a detailed kinetic soot model. Two different mathematical methods of the soot model description have been used in this work. In the first part of the work, the method of moments is presented. In addition, a so called sectional method for the soot particle size distribution function in diffusion flames has been developed.
Both of the methods have been employed for simulations in diesel like engine operating conditions. The commercial computational fluid dynamics (CFD) codes have been used in order to obtain more information of temporal and spatial soot particles size distribution inside the enclosed chamber. The predictive capabilities of the model have been validated versus experimental data for different fuels and different initial and boundary conditions. The subject of the calculations was the influence of these different values on the soot particle formation.
The sectional model was validated with laboratory diesel fuel jet flame data for an optically accessible constantvolume combustion vessel, where test data at high pressure and high temperature are available. For the validation of the soot method of moments, different optical measurements of the incylinder soot have been presented. The combustion process itself is simulated using a progress variable model for the auto ignition of a diffusion flamelet, with the sectional model calculations. Source terms for soot particle inception, surface growth, and oxidation describing the interaction of the particles with the gas phase are taken from a flamelet library for both models.
The coagulation of particles is calculated as part of the CFD calculations, based on the mean of the weighted soot mass fractions. The computations demonstrate the complex interaction between gaseous species, soot production, temperature, etc. Exclusion of any of the above effects can lead to significant errors.
Both of the methods have been employed for simulations in diesel like engine operating conditions. The commercial computational fluid dynamics (CFD) codes have been used in order to obtain more information of temporal and spatial soot particles size distribution inside the enclosed chamber. The predictive capabilities of the model have been validated versus experimental data for different fuels and different initial and boundary conditions. The subject of the calculations was the influence of these different values on the soot particle formation.
The sectional model was validated with laboratory diesel fuel jet flame data for an optically accessible constantvolume combustion vessel, where test data at high pressure and high temperature are available. For the validation of the soot method of moments, different optical measurements of the incylinder soot have been presented. The combustion process itself is simulated using a progress variable model for the auto ignition of a diffusion flamelet, with the sectional model calculations. Source terms for soot particle inception, surface growth, and oxidation describing the interaction of the particles with the gas phase are taken from a flamelet library for both models.
The coagulation of particles is calculated as part of the CFD calculations, based on the mean of the weighted soot mass fractions. The computations demonstrate the complex interaction between gaseous species, soot production, temperature, etc. Exclusion of any of the above effects can lead to significant errors.
Original language  English 

Qualification  Doctor 
Awarding Institution 

Supervisors/Advisors 

Award date  2006 May 5 
Publisher  
Publication status  Published  2006 
Bibliographical note
Defence detailsDate: 20060505
Time: 10:15
Place: Room B,Department of Physics, Professorsgatan 1, Lund Institute of Technology
External reviewer(s)
Name: D`Anna, Andrea
Title: Professor
Affiliation: Universita di Napoli Frederico 2

Subject classification (UKÄ)
 Atom and Molecular Physics and Optics
Keywords
 Gaser
 fluiddynamik
 plasma
 Motors and propulsion systems
 Motorer
 framdrivningssystem
 plasmas
 fluid dynamics
 Gases
 Fysik
 Physics
 Computational Fluid Dynamics
 Sectional Method
 Method of Moments
 Diesel Like Engine Condition
 Distribution Function
 Detailed Kinetic Soot Model
 Soot Particle Size