Simulation and analysis of the soot particle size distribution in a turbulent nonpremixed flame

Handle URI:
http://hdl.handle.net/10754/622907
Title:
Simulation and analysis of the soot particle size distribution in a turbulent nonpremixed flame
Authors:
Lucchesi, Marco; Abdelgadir, Ahmed Gamaleldin ( 0000-0001-6907-2211 ) ; Attili, Antonio; Bisetti, Fabrizio ( 0000-0001-5162-7805 )
Abstract:
A modeling framework based on Direct Simulation Monte Carlo (DSMC) is employed to simulate the evolution of the soot particle size distribution in turbulent sooting flames. The stochastic reactor describes the evolution of soot in fluid parcels following Lagrangian trajectories in a turbulent flow field. The trajectories are sampled from a Direct Numerical Simulation (DNS) of a n-heptane turbulent nonpremixed flame. The DSMC method is validated against experimentally measured size distributions in laminar premixed flames and found to reproduce quantitatively the experimental results, including the appearance of the second mode at large aggregate sizes and the presence of a trough at mobility diameters in the range 3–8 nm. The model is then applied to the simulation of soot formation and growth in simplified configurations featuring a constant concentration of soot precursors and the evolution of the size distribution in time is found to depend on the intensity of the nucleation rate. Higher nucleation rates lead to a higher peak in number density and to the size distribution attaining its second mode sooner. The ensemble-averaged PSDF in the turbulent flame is computed from individual samples of the PSDF from large sets of Lagrangian trajectories. This statistical measure is equivalent to time-averaged, scanning mobility particle size (SMPS) measurements in turbulent flames. Although individual trajectories display strong bimodality as in laminar flames, the ensemble-average PSDF possesses only one mode and a long, broad tail, which implies significant polydispersity induced by turbulence. Our results agree very well with SMPS measurements available in the literature. Conditioning on key features of the trajectory, such as mixture fraction or radial locations does not reduce the scatter in the size distributions and the ensemble-averaged PSDF remains broad. The results highlight and explain the important role of turbulence in broadening the size distribution of particles in turbulent sooting flames.
KAUST Department:
Clean Combustion Research Center; Physical Sciences and Engineering (PSE) Division
Citation:
Lucchesi M, Abdelgadir A, Attili A, Bisetti F (2017) Simulation and analysis of the soot particle size distribution in a turbulent nonpremixed flame. Combustion and Flame 178: 35–45. Available: http://dx.doi.org/10.1016/j.combustflame.2017.01.002.
Publisher:
Elsevier BV
Journal:
Combustion and Flame
Issue Date:
5-Feb-2017
DOI:
10.1016/j.combustflame.2017.01.002
Type:
Article
ISSN:
0010-2180
Sponsors:
This research was funded by King Abdullah University of Science and Technology (KAUST) and made use of the computational resources managed by IT Research Computing at KAUST.
Additional Links:
http://www.sciencedirect.com/science/article/pii/S0010218017300020
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Clean Combustion Research Center

Full metadata record

DC FieldValue Language
dc.contributor.authorLucchesi, Marcoen
dc.contributor.authorAbdelgadir, Ahmed Gamaleldinen
dc.contributor.authorAttili, Antonioen
dc.contributor.authorBisetti, Fabrizioen
dc.date.accessioned2017-02-15T08:32:16Z-
dc.date.available2017-02-15T08:32:16Z-
dc.date.issued2017-02-05en
dc.identifier.citationLucchesi M, Abdelgadir A, Attili A, Bisetti F (2017) Simulation and analysis of the soot particle size distribution in a turbulent nonpremixed flame. Combustion and Flame 178: 35–45. Available: http://dx.doi.org/10.1016/j.combustflame.2017.01.002.en
dc.identifier.issn0010-2180en
dc.identifier.doi10.1016/j.combustflame.2017.01.002en
dc.identifier.urihttp://hdl.handle.net/10754/622907-
dc.description.abstractA modeling framework based on Direct Simulation Monte Carlo (DSMC) is employed to simulate the evolution of the soot particle size distribution in turbulent sooting flames. The stochastic reactor describes the evolution of soot in fluid parcels following Lagrangian trajectories in a turbulent flow field. The trajectories are sampled from a Direct Numerical Simulation (DNS) of a n-heptane turbulent nonpremixed flame. The DSMC method is validated against experimentally measured size distributions in laminar premixed flames and found to reproduce quantitatively the experimental results, including the appearance of the second mode at large aggregate sizes and the presence of a trough at mobility diameters in the range 3–8 nm. The model is then applied to the simulation of soot formation and growth in simplified configurations featuring a constant concentration of soot precursors and the evolution of the size distribution in time is found to depend on the intensity of the nucleation rate. Higher nucleation rates lead to a higher peak in number density and to the size distribution attaining its second mode sooner. The ensemble-averaged PSDF in the turbulent flame is computed from individual samples of the PSDF from large sets of Lagrangian trajectories. This statistical measure is equivalent to time-averaged, scanning mobility particle size (SMPS) measurements in turbulent flames. Although individual trajectories display strong bimodality as in laminar flames, the ensemble-average PSDF possesses only one mode and a long, broad tail, which implies significant polydispersity induced by turbulence. Our results agree very well with SMPS measurements available in the literature. Conditioning on key features of the trajectory, such as mixture fraction or radial locations does not reduce the scatter in the size distributions and the ensemble-averaged PSDF remains broad. The results highlight and explain the important role of turbulence in broadening the size distribution of particles in turbulent sooting flames.en
dc.description.sponsorshipThis research was funded by King Abdullah University of Science and Technology (KAUST) and made use of the computational resources managed by IT Research Computing at KAUST.en
dc.publisherElsevier BVen
dc.relation.urlhttp://www.sciencedirect.com/science/article/pii/S0010218017300020en
dc.subjectMonte carlo simulationsen
dc.subjectSooten
dc.subjectLagrangian statisticsen
dc.subjectTurbulent flamesen
dc.titleSimulation and analysis of the soot particle size distribution in a turbulent nonpremixed flameen
dc.typeArticleen
dc.contributor.departmentClean Combustion Research Centeren
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.identifier.journalCombustion and Flameen
dc.contributor.institutionDipartimento di Ingegneria Meccanica ed Aerospaziale, Università “La Sapienza” di Roma, Rome 00184, Italyen
dc.contributor.institutionInstitute for Combustion Technology, RWTH Aachen University, Aachen 52056, Germanyen
dc.contributor.institutionDepartment of Aerospace Engineering and Engineering Mechanics, University of Texas at Austin, Austin, TX 78712-1085, USAen
kaust.authorLucchesi, Marcoen
kaust.authorAbdelgadir, Ahmed Gamaleldinen
kaust.authorAttili, Antonioen
kaust.authorBisetti, Fabrizioen
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