---
_id: '24508'
abstract:
- lang: eng
text: Liquid atomization determines the initial conditions for flame formation and
particle synthesis. Without a stable flame, high droplet velocities and thus short
droplet residence time in the flame may lead to droplets being injected into an
extinguished flame, which influences synthesis and final particle output. An experimental
investigation of spray formation and flame stability is performed through high-speed
visualization. Targeted variation of nozzle geometry is applied to improve spray-flame
interaction and compared to a standardized burner. Timescales of spray density
and flame fluctuations are quantified and compared, where the latter were significantly
larger and hence not correlated. Instead, dispersion gas forms a barrier between
spray phase and pilot flame; hence, ignition depends on large liquid lumps with
high radial momentum to break through the dispersion gas for spray ignition. Angling
of dispersion gas flow increases radial shear and turbulence and leads to refined
atomization and improved flame stability. To investigate the nozzle influence
on particle formation, particle characteristics are examined by online and offline
analytics with focus on particle structures and product purity. The modified nozzle
produced smaller primary particle sizes, thus indicating a sensitivity of sintering
dominance on the nozzle geometry. Impurities impact the examination of particle
structures and general particle functionality. Carbon contamination was apparent
in synthesized particles and also indicated sensitivity to nozzle geometry. Discrepancies
to literature data are discussed regarding differences in flame activity and droplet
characteristics. The report highlights, how product characteristics can differ
crucially due to changes in nozzle geometry despite comparable operating conditions.
author:
- first_name: M.
full_name: Bieber, M.
last_name: Bieber
- first_name: M.
full_name: Al-Khatib, M.
last_name: Al-Khatib
- first_name: F.
full_name: Fröde, F.
last_name: Fröde
- first_name: H.
full_name: Pitsch, H.
last_name: Pitsch
- first_name: M. A.
full_name: Reddemann, M. A.
last_name: Reddemann
- first_name: H-J.
full_name: Schmid, H-J.
last_name: Schmid
- first_name: R.
full_name: Tischendorf, R.
last_name: Tischendorf
- first_name: R.
full_name: Kneer, R.
last_name: Kneer
citation:
ama: Bieber M, Al-Khatib M, Fröde F, et al. Influence of angled dispersion gas on
coaxial atomization, spray and flame formation in the context of spray-flame synthesis
of nanoparticles. Experiments in Fluids. Published online 2021. doi:10.1007/s00348-021-03196-6
apa: Bieber, M., Al-Khatib, M., Fröde, F., Pitsch, H., Reddemann, M. A., Schmid,
H.-J., Tischendorf, R., & Kneer, R. (2021). Influence of angled dispersion
gas on coaxial atomization, spray and flame formation in the context of spray-flame
synthesis of nanoparticles. Experiments in Fluids. https://doi.org/10.1007/s00348-021-03196-6
bibtex: '@article{Bieber_Al-Khatib_Fröde_Pitsch_Reddemann_Schmid_Tischendorf_Kneer_2021,
title={Influence of angled dispersion gas on coaxial atomization, spray and flame
formation in the context of spray-flame synthesis of nanoparticles}, DOI={10.1007/s00348-021-03196-6},
journal={Experiments in Fluids}, author={Bieber, M. and Al-Khatib, M. and Fröde,
F. and Pitsch, H. and Reddemann, M. A. and Schmid, H-J. and Tischendorf, R. and
Kneer, R.}, year={2021} }'
chicago: Bieber, M., M. Al-Khatib, F. Fröde, H. Pitsch, M. A. Reddemann, H-J. Schmid,
R. Tischendorf, and R. Kneer. “Influence of Angled Dispersion Gas on Coaxial Atomization,
Spray and Flame Formation in the Context of Spray-Flame Synthesis of Nanoparticles.”
Experiments in Fluids, 2021. https://doi.org/10.1007/s00348-021-03196-6.
ieee: 'M. Bieber et al., “Influence of angled dispersion gas on coaxial atomization,
spray and flame formation in the context of spray-flame synthesis of nanoparticles,”
Experiments in Fluids, 2021, doi: 10.1007/s00348-021-03196-6.'
mla: Bieber, M., et al. “Influence of Angled Dispersion Gas on Coaxial Atomization,
Spray and Flame Formation in the Context of Spray-Flame Synthesis of Nanoparticles.”
Experiments in Fluids, 2021, doi:10.1007/s00348-021-03196-6.
short: M. Bieber, M. Al-Khatib, F. Fröde, H. Pitsch, M.A. Reddemann, H.-J. Schmid,
R. Tischendorf, R. Kneer, Experiments in Fluids (2021).
date_created: 2021-09-15T10:29:51Z
date_updated: 2022-01-06T06:56:26Z
ddc:
- '620'
doi: 10.1007/s00348-021-03196-6
file:
- access_level: closed
content_type: application/pdf
creator: ricardo
date_created: 2021-09-28T08:38:19Z
date_updated: 2021-09-28T08:38:19Z
file_id: '25055'
file_name: Influence of angled dispersion gas.pdf
file_size: 2667249
relation: main_file
success: 1
file_date_updated: 2021-09-28T08:38:19Z
has_accepted_license: '1'
language:
- iso: eng
publication: Experiments in Fluids
publication_identifier:
issn:
- 0723-4864
- 1432-1114
publication_status: published
status: public
title: Influence of angled dispersion gas on coaxial atomization, spray and flame
formation in the context of spray-flame synthesis of nanoparticles
type: journal_article
user_id: '67002'
year: '2021'
...
---
_id: '24124'
author:
- first_name: Venkatesh
full_name: Inguva, Venkatesh
last_name: Inguva
- first_name: Jonathan P.
full_name: Rothstein, Jonathan P.
last_name: Rothstein
- first_name: Osman
full_name: Bilsel, Osman
last_name: Bilsel
- first_name: Blair J.
full_name: Perot, Blair J.
last_name: Perot
citation:
ama: Inguva V, Rothstein JP, Bilsel O, Perot BJ. High-speed velocimetry in microfluidic
protein mixers using confocal fluorescence decay microscopy. Experiments in
Fluids. Published online 2018. doi:10.1007/s00348-018-2630-0
apa: Inguva, V., Rothstein, J. P., Bilsel, O., & Perot, B. J. (2018). High-speed
velocimetry in microfluidic protein mixers using confocal fluorescence decay microscopy.
Experiments in Fluids. https://doi.org/10.1007/s00348-018-2630-0
bibtex: '@article{Inguva_Rothstein_Bilsel_Perot_2018, title={High-speed velocimetry
in microfluidic protein mixers using confocal fluorescence decay microscopy},
DOI={10.1007/s00348-018-2630-0},
journal={Experiments in Fluids}, author={Inguva, Venkatesh and Rothstein, Jonathan
P. and Bilsel, Osman and Perot, Blair J.}, year={2018} }'
chicago: Inguva, Venkatesh, Jonathan P. Rothstein, Osman Bilsel, and Blair J. Perot.
“High-Speed Velocimetry in Microfluidic Protein Mixers Using Confocal Fluorescence
Decay Microscopy.” Experiments in Fluids, 2018. https://doi.org/10.1007/s00348-018-2630-0.
ieee: 'V. Inguva, J. P. Rothstein, O. Bilsel, and B. J. Perot, “High-speed velocimetry
in microfluidic protein mixers using confocal fluorescence decay microscopy,”
Experiments in Fluids, 2018, doi: 10.1007/s00348-018-2630-0.'
mla: Inguva, Venkatesh, et al. “High-Speed Velocimetry in Microfluidic Protein Mixers
Using Confocal Fluorescence Decay Microscopy.” Experiments in Fluids, 2018,
doi:10.1007/s00348-018-2630-0.
short: V. Inguva, J.P. Rothstein, O. Bilsel, B.J. Perot, Experiments in Fluids (2018).
date_created: 2021-09-10T07:55:40Z
date_updated: 2022-01-06T06:56:07Z
doi: 10.1007/s00348-018-2630-0
language:
- iso: eng
publication: Experiments in Fluids
publication_identifier:
issn:
- 0723-4864
- 1432-1114
publication_status: published
status: public
title: High-speed velocimetry in microfluidic protein mixers using confocal fluorescence
decay microscopy
type: journal_article
user_id: '75069'
year: '2018'
...
---
_id: '21947'
abstract:
- lang: eng
text: Wall slip is a long-known phenomenon in the field of rheology. Nevertheless,
the origin and the evolution are not completely clear yet. Regarding suspensions,
the effect becomes even more complicated, because different mechanisms like pure
slip or slip due to particle migration have to be taken into account. Furthermore,
suspensions themselves show many flow anomalies and the isolation of slip is complicated.
In order to develop working physical models, further insight is necessary. In
this work, we measured experimentally the wall slip velocities of different highly
filled suspensions in a rectangular slit die directly with respect to the particle
concentration and the particle size. The slip velocities were obtained using a
particle image velocimetry (PIV) system. The suspensions consisting of a castor
oil–cinnamon oil blend and PMMA particles were matched in terms of refractive
indexes to appear transparent. Hereby, possible optical path lengths larger than
15 mm were achieved. The slip velocities were found to be in a quadratic relation
to the wall shear stress. Furthermore, the overall flow rate as well as the particle
concentration has a direct influence on the slip. Concerning the shear stress,
there seem to be two regions of slip with different physical characteristics.
Furthermore, we estimated the slip layer thickness directly from the velocity
profiles and propose a new interpretation. The PIV technique is used to investigate
the viscosity and implicit the concentration profile in the slit die. It is shown
that the particle migration process is quite fast.
article_type: original
author:
- first_name: Steffen
full_name: Jesinghausen, Steffen
id: '3959'
last_name: Jesinghausen
orcid: https://orcid.org/0000-0003-2611-5298
- first_name: Rene
full_name: Weiffen, Rene
last_name: Weiffen
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
id: '464'
last_name: Schmid
citation:
ama: Jesinghausen S, Weiffen R, Schmid H-J. Direct measurement of wall slip and
slip layer thickness of non-Brownian hard-sphere suspensions in rectangular channel
flows. Experiments in Fluids. Published online 2016. doi:10.1007/s00348-016-2241-6
apa: Jesinghausen, S., Weiffen, R., & Schmid, H.-J. (2016). Direct measurement
of wall slip and slip layer thickness of non-Brownian hard-sphere suspensions
in rectangular channel flows. Experiments in Fluids. https://doi.org/10.1007/s00348-016-2241-6
bibtex: '@article{Jesinghausen_Weiffen_Schmid_2016, title={Direct measurement of
wall slip and slip layer thickness of non-Brownian hard-sphere suspensions in
rectangular channel flows}, DOI={10.1007/s00348-016-2241-6},
journal={Experiments in Fluids}, author={Jesinghausen, Steffen and Weiffen, Rene
and Schmid, Hans-Joachim}, year={2016} }'
chicago: Jesinghausen, Steffen, Rene Weiffen, and Hans-Joachim Schmid. “Direct Measurement
of Wall Slip and Slip Layer Thickness of Non-Brownian Hard-Sphere Suspensions
in Rectangular Channel Flows.” Experiments in Fluids, 2016. https://doi.org/10.1007/s00348-016-2241-6.
ieee: 'S. Jesinghausen, R. Weiffen, and H.-J. Schmid, “Direct measurement of wall
slip and slip layer thickness of non-Brownian hard-sphere suspensions in rectangular
channel flows,” Experiments in Fluids, 2016, doi: 10.1007/s00348-016-2241-6.'
mla: Jesinghausen, Steffen, et al. “Direct Measurement of Wall Slip and Slip Layer
Thickness of Non-Brownian Hard-Sphere Suspensions in Rectangular Channel Flows.”
Experiments in Fluids, 2016, doi:10.1007/s00348-016-2241-6.
short: S. Jesinghausen, R. Weiffen, H.-J. Schmid, Experiments in Fluids (2016).
date_created: 2021-05-04T08:47:31Z
date_updated: 2023-01-17T07:37:53Z
department:
- _id: '150'
- _id: '9'
doi: 10.1007/s00348-016-2241-6
keyword:
- Rheology
- Wall Slip
- Slip
- apparent slip
- suspension
language:
- iso: eng
main_file_link:
- url: https://link.springer.com/article/10.1007/s00348-016-2241-6
publication: Experiments in Fluids
publication_identifier:
issn:
- 0723-4864
- 1432-1114
publication_status: published
quality_controlled: '1'
status: public
title: Direct measurement of wall slip and slip layer thickness of non-Brownian hard-sphere
suspensions in rectangular channel flows
type: journal_article
user_id: '3959'
year: '2016'
...