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Full Cycle Engine Simulations with Detailed Chemistry

Gogan, Adina LU (2006)
Abstract
The modeling work developed in this thesis can be divided in two main areas of investigations: autoignition related to spark ignition engine and combustion and emissions formation in relation to diesel engines.



A first version of a detailed kinetics engine simulation program, extended to handle full cycle calculations, was employed in order to demonstrate the strong effect that nitric oxide from the residual gas has on the autoignition onset. It was found that a concentration of about 500 ppm in the intake gas determines a maximal promotion of autoignition.



Increased simulation capabilities were achieved by integrating the in house detailed kinetic code into a commercial 1-D engine program. By this it... (More)
The modeling work developed in this thesis can be divided in two main areas of investigations: autoignition related to spark ignition engine and combustion and emissions formation in relation to diesel engines.



A first version of a detailed kinetics engine simulation program, extended to handle full cycle calculations, was employed in order to demonstrate the strong effect that nitric oxide from the residual gas has on the autoignition onset. It was found that a concentration of about 500 ppm in the intake gas determines a maximal promotion of autoignition.



Increased simulation capabilities were achieved by integrating the in house detailed kinetic code into a commercial 1-D engine program. By this it was possible on one hand to have a simulation tool able to handle detailed kinetics and thus have control over combustion and emissions, and on the other hand to monitor global engine operation conditions.



Further accuracy on autoignition was achieved by employing a stochastic reactor model (SRM) for spark ignition engine calculations. Based on the probability density function (PDF) this approach was able to model phenomena with strong influence on engine knock as: turbulent mixing and inhomogeneities, phenomena usually neglected by regular existing engine programs. While keeping computational time low and still using detailed chemistry, good correlative results were obtained with the stochastic approach.



For the second part of the work, the stochastic reactor model was applied for diesel engine combustion and emissions investigations. The purpose of this implementation was primarily the calculation of NOx emissions and soot within diesel engines. Soot calculations were based on the method of moments. Comparisons of soot production with measured data from a carbon black reactor indicate good agreement. The diesel SRM model was applied on a FIAT car engine and on a low speed marine engine. The model is capable to correlate the ignition timing and to indicate the trends in NOx and soot generation. (Less)
Abstract (Swedish)
Popular Abstract in Swedish

Modelleringsarbetet utvecklat i denna avhandling, kan delas in i två huvudområden: självantändning i ottomotorer, samt förbränning och emissioner i dieselmotorer.



En första version av ett motorsimuleringsprogram med detaljerad kemisk kinetik, utökad för att innefatta full-cykel beräkningar, användes för att visa den starka påverkan som kväveoxider i restgaser har på självantändning och dess tidpunkt. Beräkningarna visade att en koncentration på ca 500 ppm i insugsgaserna ger största bidrag för självantändning.



Utökade simuleringsmöjligheter erhölls genom att integrera den internt utvecklade koden med ett kommersiellt 1-D motorsimuleringsprogram. Genom denna... (More)
Popular Abstract in Swedish

Modelleringsarbetet utvecklat i denna avhandling, kan delas in i två huvudområden: självantändning i ottomotorer, samt förbränning och emissioner i dieselmotorer.



En första version av ett motorsimuleringsprogram med detaljerad kemisk kinetik, utökad för att innefatta full-cykel beräkningar, användes för att visa den starka påverkan som kväveoxider i restgaser har på självantändning och dess tidpunkt. Beräkningarna visade att en koncentration på ca 500 ppm i insugsgaserna ger största bidrag för självantändning.



Utökade simuleringsmöjligheter erhölls genom att integrera den internt utvecklade koden med ett kommersiellt 1-D motorsimuleringsprogram. Genom denna integration var det möjligt att simulera förbränning och emissioner med detaljerad kemisk kinetik, samtidigt som de globala driftsparametrarna kunde övervakas.



Större noggrannhet för beräkning av självantändning erhölls genom användandet av en stokastisk reaktor modell (SRM) för ottomotorberäkningar. Baserad på probability density function (PDF) är det med denna model möjligt att modellera fenomen som har en stark påverkan på motorknack, såsom: turbulent omblandning och inhomogeniteter, fenomen som oftast lämnas utan hänsyn i normala befintliga motorsimulerings program. Samtidigt som beräkningstiden kan hållas nere, ger den stokastiska modellen goda och korrelerade resultat tack vare att detaljerad kemi kan användas.



I den andra delen av avhandlingen, utvecklades den stokastiska reaktor modellen, för undersökning av dieselmotorers förbränning och emissioner. Syftet med denna implementation var huvudsakligen för beräkningar av NOx- och sotemissioner. Sotberäkningar gjordes med moment-metoden som visar god korrelation med mätningar gjorda för kimrökreaktorer. Den utvecklade Diesel-SRM modellen användes för undersökningar på dels en FIAT personbilsmotor, samt dels för en lågvarvig skeppsmotor. Modellen är kapabel att korrelera tändtidpunkt, samt indikera trender för NOx- så väl som för sotgenerering. (Less)
Please use this url to cite or link to this publication:
author
supervisor
opponent
  • Principal Scientist Kalghatgi, Gautam, Shell Global Solutions U.K
organization
publishing date
type
Thesis
publication status
published
subject
keywords
plasmas, Gaser, Gases, fluid dynamics, aktuariematematik, programmering, operationsanalys, Statistik, actuarial mathematics, programming, operations research, Statistics, detailed kinetics, emissions, engine knock, autoignition, modeling, spark ignition engine, diesel engine, fluiddynamik, plasma, Technological sciences, Teknik, Thermal engineering, applied thermodynamics, Termisk teknik, termodynamik, Motors and propulsion systems, Motorer, framdrivningssystem, stochastic reactor model
pages
160 pages
publisher
KFS AB
defense location
Room M:2469, M-Building, Ole Römers väg 1, Lund Institute of Technology
defense date
2006-03-27 10:15:00
external identifiers
  • other:ISRN:LUTMDN/TMHP--06/1038--SE
ISBN
978-91-628-6765-2
language
English
LU publication?
yes
id
cd52555d-e442-47d0-bf23-e98ffc5d5b3b (old id 546318)
date added to LUP
2016-04-01 16:08:08
date last changed
2018-11-21 20:39:01
@phdthesis{cd52555d-e442-47d0-bf23-e98ffc5d5b3b,
  abstract     = {The modeling work developed in this thesis can be divided in two main areas of investigations: autoignition related to spark ignition engine and combustion and emissions formation in relation to diesel engines.<br/><br>
<br/><br>
A first version of a detailed kinetics engine simulation program, extended to handle full cycle calculations, was employed in order to demonstrate the strong effect that nitric oxide from the residual gas has on the autoignition onset. It was found that a concentration of about 500 ppm in the intake gas determines a maximal promotion of autoignition.<br/><br>
<br/><br>
Increased simulation capabilities were achieved by integrating the in house detailed kinetic code into a commercial 1-D engine program. By this it was possible on one hand to have a simulation tool able to handle detailed kinetics and thus have control over combustion and emissions, and on the other hand to monitor global engine operation conditions.<br/><br>
<br/><br>
Further accuracy on autoignition was achieved by employing a stochastic reactor model (SRM) for spark ignition engine calculations. Based on the probability density function (PDF) this approach was able to model phenomena with strong influence on engine knock as: turbulent mixing and inhomogeneities, phenomena usually neglected by regular existing engine programs. While keeping computational time low and still using detailed chemistry, good correlative results were obtained with the stochastic approach.<br/><br>
<br/><br>
For the second part of the work, the stochastic reactor model was applied for diesel engine combustion and emissions investigations. The purpose of this implementation was primarily the calculation of NOx emissions and soot within diesel engines. Soot calculations were based on the method of moments. Comparisons of soot production with measured data from a carbon black reactor indicate good agreement. The diesel SRM model was applied on a FIAT car engine and on a low speed marine engine. The model is capable to correlate the ignition timing and to indicate the trends in NOx and soot generation.},
  author       = {Gogan, Adina},
  isbn         = {978-91-628-6765-2},
  language     = {eng},
  publisher    = {KFS AB},
  school       = {Lund University},
  title        = {Full Cycle Engine Simulations with Detailed Chemistry},
  year         = {2006},
}