The present paper uses Langevin dynamics (LD) to investigate the aggregation of
soot nano-particles in turbulent flows. Interparticle forces are included, and
the computation of the individual particles by LD is retained even after
aggregate formation such that collision events and locations can be based on
center-to-center particle distances without invoking any modelling assumptions
of aggregate shape and/or collision frequency. We focus on the interactions
between the specific hydrodynamic conditions and the particle properties and
their effect on the resulting agglomerates' morphologies. The morphology is
characterized by the fractal dimension, Df. Computations of particle
aggregation in homogeneous isotropic turbulence and in shear flows dominated by
counter-rotating vortices with a wide range of turbulence intensities and
particle sizes indicate that the evolution of the agglomerates' shapes can be
adequately parameterized by the size of the agglomerates and the Knudsen and
Péclet numbers, the latter being based on the smallest turbulence scales. The
computations further suggest that the shapes of agglomerates of certain sizes
are relatively independent of time and relatively insensitive to larger
turbulence structures. The fractal dimensions are modelled as functions of
radius of gyration, Kn and Pe. The fitted expressions show good agreement with
the LD simulations and represent the entire growth process of the agglomerates.
A direct comparison of selected aggregates with experimental data shows very
good qualitative agreement. A thorough quantitative validation of the evolution
of the computed aggregate characteristics is, however, presently hindered by
the challenges for and therefore lack of suitable experiments under
appropriately controlled conditions.
%0 Journal Article
%1 inci2017langevin
%A Inci, Gizem
%A Kronenburg, Andreas
%A Weeber, Rudolf
%A Pflüger, Dirk
%D 2017
%I Springer
%J Flow, Turbulence and Combustion
%K Aggregation;_Dissipation_rate;_Langevin_dynamics;_Soot_particles;_Turbulence from:leiterrl
%P 1--21
%R 10.1007/s10494-016-9797-3
%T Langevin Dynamics Simulation of Transport and Aggregation of Soot Nano-particles in Turbulent Flows
%U http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2017-03&engl=0
%X The present paper uses Langevin dynamics (LD) to investigate the aggregation of
soot nano-particles in turbulent flows. Interparticle forces are included, and
the computation of the individual particles by LD is retained even after
aggregate formation such that collision events and locations can be based on
center-to-center particle distances without invoking any modelling assumptions
of aggregate shape and/or collision frequency. We focus on the interactions
between the specific hydrodynamic conditions and the particle properties and
their effect on the resulting agglomerates' morphologies. The morphology is
characterized by the fractal dimension, Df. Computations of particle
aggregation in homogeneous isotropic turbulence and in shear flows dominated by
counter-rotating vortices with a wide range of turbulence intensities and
particle sizes indicate that the evolution of the agglomerates' shapes can be
adequately parameterized by the size of the agglomerates and the Knudsen and
Péclet numbers, the latter being based on the smallest turbulence scales. The
computations further suggest that the shapes of agglomerates of certain sizes
are relatively independent of time and relatively insensitive to larger
turbulence structures. The fractal dimensions are modelled as functions of
radius of gyration, Kn and Pe. The fitted expressions show good agreement with
the LD simulations and represent the entire growth process of the agglomerates.
A direct comparison of selected aggregates with experimental data shows very
good qualitative agreement. A thorough quantitative validation of the evolution
of the computed aggregate characteristics is, however, presently hindered by
the challenges for and therefore lack of suitable experiments under
appropriately controlled conditions.
@article{inci2017langevin,
abstract = {The present paper uses Langevin dynamics (LD) to investigate the aggregation of
soot nano-particles in turbulent flows. Interparticle forces are included, and
the computation of the individual particles by LD is retained even after
aggregate formation such that collision events and locations can be based on
center-to-center particle distances without invoking any modelling assumptions
of aggregate shape and/or collision frequency. We focus on the interactions
between the specific hydrodynamic conditions and the particle properties and
their effect on the resulting agglomerates' morphologies. The morphology is
characterized by the fractal dimension, Df. Computations of particle
aggregation in homogeneous isotropic turbulence and in shear flows dominated by
counter-rotating vortices with a wide range of turbulence intensities and
particle sizes indicate that the evolution of the agglomerates' shapes can be
adequately parameterized by the size of the agglomerates and the Knudsen and
P{\'e}clet numbers, the latter being based on the smallest turbulence scales. The
computations further suggest that the shapes of agglomerates of certain sizes
are relatively independent of time and relatively insensitive to larger
turbulence structures. The fractal dimensions are modelled as functions of
radius of gyration, Kn and Pe. The fitted expressions show good agreement with
the LD simulations and represent the entire growth process of the agglomerates.
A direct comparison of selected aggregates with experimental data shows very
good qualitative agreement. A thorough quantitative validation of the evolution
of the computed aggregate characteristics is, however, presently hindered by
the challenges for and therefore lack of suitable experiments under
appropriately controlled conditions.},
added-at = {2020-07-27T15:42:32.000+0200},
author = {Inci, Gizem and Kronenburg, Andreas and Weeber, Rudolf and Pfl{\"u}ger, Dirk},
biburl = {https://puma.ub.uni-stuttgart.de/bibtex/20c07613289fb2f0af403f4339521e900/ipvs-sc},
cr-category = {J.2 Physical Sciences and Engineering},
department = {Universit{\"a}t Stuttgart, Institut f{\"u}r Parallele und Verteilte Systeme, Simulation gro{\ss}er Systeme},
doi = {10.1007/s10494-016-9797-3},
interhash = {2546599fe5f1364041bbd8740528515a},
intrahash = {0c07613289fb2f0af403f4339521e900},
issn = {1573-1987},
journal = {Flow, Turbulence and Combustion},
keywords = {Aggregation;_Dissipation_rate;_Langevin_dynamics;_Soot_particles;_Turbulence from:leiterrl},
language = {Englisch},
month = {Januar},
pages = {1--21},
publisher = {Springer},
timestamp = {2020-07-27T13:42:32.000+0200},
title = {{Langevin Dynamics Simulation of Transport and Aggregation of Soot Nano-particles in Turbulent Flows}},
type = {Artikel in Zeitschrift},
url = {http://www2.informatik.uni-stuttgart.de/cgi-bin/NCSTRL/NCSTRL_view.pl?id=ART-2017-03&engl=0},
year = 2017
}