---
_id: '36983'
abstract:
- lang: eng
text: "AbstractThe use of structured measuring
systems to prevent wall slip is a common approach to obtain absolute rheological
values. Typically, only the minimum distance between the measuring surfaces is
used for further calculation, implying that no flow occurs between the structural
elements. But this assumption is misleading, and a gap correction is necessary.
To determine the radius correction $$\\Delta
r$$\r\n
\ \r\n Δ\r\n r\r\n
\ \r\n
for specific geometries, we conducted investigations on three Newtonian fluids
(two silicon oils and one suspension considered to be Newtonian in the relevant
shear rate range). The results show that $$\\Delta
r$$\r\n
\ \r\n Δ\r\n r\r\n
\ \r\n
is not only shear- and material-independent, but geometry-dependent, providing
a Newtonian flow behaviour in a similar viscosity range. Therefore, a correction
value can be determined with only minute deviations in different Newtonian fluids.
As the conducted laboratory measurements are very time-consuming and expensive,
a CFD-approach with only very small deviations was additionally developed and
compared for validation purposes. Therefore, simulation is an effective and resource-efficient
alternative to the presented laboratory measurements to determine $$\\Delta
r$$\r\n
\ \r\n Δ\r\n r\r\n
\ \r\n
for the correction of structured coaxial geometries even for non-Newtonian fluids
in the future."
article_type: original
author:
- first_name: Sebastian
full_name: Josch, Sebastian
id: '38243'
last_name: Josch
- first_name: Steffen
full_name: Jesinghausen, Steffen
id: '3959'
last_name: Jesinghausen
orcid: https://orcid.org/0000-0003-2611-5298
- first_name: Christopher
full_name: Dechert, Christopher
id: '69828'
last_name: Dechert
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
id: '464'
last_name: Schmid
orcid: 000-0001-8590-1921
citation:
ama: Josch S, Jesinghausen S, Dechert C, Schmid H-J. Experimental and simulative
determination and correction of the effective gap extension in structured coaxial
measuring systems. Rheologica Acta. Published online 2023. doi:10.1007/s00397-023-01383-2
apa: Josch, S., Jesinghausen, S., Dechert, C., & Schmid, H.-J. (2023). Experimental
and simulative determination and correction of the effective gap extension in
structured coaxial measuring systems. Rheologica Acta. https://doi.org/10.1007/s00397-023-01383-2
bibtex: '@article{Josch_Jesinghausen_Dechert_Schmid_2023, title={Experimental and
simulative determination and correction of the effective gap extension in structured
coaxial measuring systems}, DOI={10.1007/s00397-023-01383-2},
journal={Rheologica Acta}, publisher={Springer Science and Business Media LLC},
author={Josch, Sebastian and Jesinghausen, Steffen and Dechert, Christopher and
Schmid, Hans-Joachim}, year={2023} }'
chicago: Josch, Sebastian, Steffen Jesinghausen, Christopher Dechert, and Hans-Joachim
Schmid. “Experimental and Simulative Determination and Correction of the Effective
Gap Extension in Structured Coaxial Measuring Systems.” Rheologica Acta,
2023. https://doi.org/10.1007/s00397-023-01383-2.
ieee: 'S. Josch, S. Jesinghausen, C. Dechert, and H.-J. Schmid, “Experimental and
simulative determination and correction of the effective gap extension in structured
coaxial measuring systems,” Rheologica Acta, 2023, doi: 10.1007/s00397-023-01383-2.'
mla: Josch, Sebastian, et al. “Experimental and Simulative Determination and Correction
of the Effective Gap Extension in Structured Coaxial Measuring Systems.” Rheologica
Acta, Springer Science and Business Media LLC, 2023, doi:10.1007/s00397-023-01383-2.
short: S. Josch, S. Jesinghausen, C. Dechert, H.-J. Schmid, Rheologica Acta (2023).
date_created: 2023-01-17T08:04:24Z
date_updated: 2023-03-14T07:41:28Z
department:
- _id: '150'
doi: 10.1007/s00397-023-01383-2
keyword:
- rheology
- rheometry
- suspension
- coaxial
- correction
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://link.springer.com/article/10.1007/s00397-023-01383-2
oa: '1'
publication: Rheologica Acta
publication_identifier:
issn:
- 0035-4511
- 1435-1528
publication_status: published
publisher: Springer Science and Business Media LLC
quality_controlled: '1'
status: public
title: Experimental and simulative determination and correction of the effective gap
extension in structured coaxial measuring systems
type: journal_article
user_id: '3959'
year: '2023'
...
---
_id: '31035'
abstract:
- lang: eng
text: AbstractFurther innovation in the field of
selective laser sintering (SLS) is strongly connected to the availability of new
materials since the market is dominated by polyamide 12 (>90%). The aim of
this publication is to develop a descriptive model for the droplet formation process
in a Filament Extension Atomizer to predict the applicability to exploit further
polymers for the SLS process. The feasibility was tested, investigated and characterized
using a “Dripping out of a nozzle” setup for uniaxial extension. The droplet formation
process was then observed via high-speed camera imaging and classified for certain
parameters. The experiments were carried out using semi-diluted polyethylene oxide
(600–4000 kg/mol), glycerol and water solutions as model fluids. Driven by the
Plateau-Rayleigh instability, different types of spherical droplets were observed
and various droplet formation mechanisms demonstrated and analyzed. Based on the
experimental results, a predictive model is derived to describe various essential
parameters.
article_type: original
author:
- first_name: Moritz
full_name: Neukötter, Moritz
id: '45530'
last_name: Neukötter
orcid: 0000-0001-9101-8828
- first_name: Steffen
full_name: Jesinghausen, Steffen
id: '3959'
last_name: Jesinghausen
orcid: https://orcid.org/0000-0003-2611-5298
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
id: '464'
last_name: Schmid
citation:
ama: Neukötter M, Jesinghausen S, Schmid H-J. Model droplet formation in extensional
filament stretching within a Filament Extension Atomizer. Rheologica Acta.
Published online 2022. doi:10.1007/s00397-022-01339-y
apa: Neukötter, M., Jesinghausen, S., & Schmid, H.-J. (2022). Model droplet
formation in extensional filament stretching within a Filament Extension Atomizer.
Rheologica Acta. https://doi.org/10.1007/s00397-022-01339-y
bibtex: '@article{Neukötter_Jesinghausen_Schmid_2022, title={Model droplet formation
in extensional filament stretching within a Filament Extension Atomizer}, DOI={10.1007/s00397-022-01339-y},
journal={Rheologica Acta}, publisher={Springer Science and Business Media LLC},
author={Neukötter, Moritz and Jesinghausen, Steffen and Schmid, Hans-Joachim},
year={2022} }'
chicago: Neukötter, Moritz, Steffen Jesinghausen, and Hans-Joachim Schmid. “Model
Droplet Formation in Extensional Filament Stretching within a Filament Extension
Atomizer.” Rheologica Acta, 2022. https://doi.org/10.1007/s00397-022-01339-y.
ieee: 'M. Neukötter, S. Jesinghausen, and H.-J. Schmid, “Model droplet formation
in extensional filament stretching within a Filament Extension Atomizer,” Rheologica
Acta, 2022, doi: 10.1007/s00397-022-01339-y.'
mla: Neukötter, Moritz, et al. “Model Droplet Formation in Extensional Filament
Stretching within a Filament Extension Atomizer.” Rheologica Acta, Springer
Science and Business Media LLC, 2022, doi:10.1007/s00397-022-01339-y.
short: M. Neukötter, S. Jesinghausen, H.-J. Schmid, Rheologica Acta (2022).
date_created: 2022-05-03T08:12:21Z
date_updated: 2023-01-17T07:35:20Z
department:
- _id: '150'
doi: 10.1007/s00397-022-01339-y
keyword:
- Rheology
- SLS
- Lasersintering
- exensional rheology
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://link.springer.com/article/10.1007/s00397-022-01339-y
oa: '1'
publication: Rheologica Acta
publication_identifier:
issn:
- 0035-4511
- 1435-1528
publication_status: published
publisher: Springer Science and Business Media LLC
quality_controlled: '1'
status: public
title: Model droplet formation in extensional filament stretching within a Filament
Extension Atomizer
type: journal_article
user_id: '3959'
year: '2022'
...
---
_id: '43238'
author:
- first_name: Torben
full_name: Rüther, Torben
id: '76950'
last_name: Rüther
- first_name: Steffen
full_name: Jesinghausen, Steffen
id: '3959'
last_name: Jesinghausen
orcid: https://orcid.org/0000-0003-2611-5298
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
id: '464'
last_name: Schmid
orcid: 000-0001-8590-1921
citation:
ama: 'Rüther T, Jesinghausen S, Schmid H-J. A novel correction method for the shear
rate in a couette rheometer (Vortrag). In: ; 2022.'
apa: Rüther, T., Jesinghausen, S., & Schmid, H.-J. (2022). A novel correction
method for the shear rate in a couette rheometer (Vortrag). AERC , Sevilla.
bibtex: '@inproceedings{Rüther_Jesinghausen_Schmid_2022, title={A novel correction
method for the shear rate in a couette rheometer (Vortrag)}, author={Rüther, Torben
and Jesinghausen, Steffen and Schmid, Hans-Joachim}, year={2022} }'
chicago: Rüther, Torben, Steffen Jesinghausen, and Hans-Joachim Schmid. “A Novel
Correction Method for the Shear Rate in a Couette Rheometer (Vortrag),” 2022.
ieee: T. Rüther, S. Jesinghausen, and H.-J. Schmid, “A novel correction method for
the shear rate in a couette rheometer (Vortrag),” presented at the AERC , Sevilla,
2022.
mla: Rüther, Torben, et al. A Novel Correction Method for the Shear Rate in a
Couette Rheometer (Vortrag). 2022.
short: 'T. Rüther, S. Jesinghausen, H.-J. Schmid, in: 2022.'
conference:
end_date: 2022-04-28
location: Sevilla
name: 'AERC '
start_date: 2022-04-26
date_created: 2023-03-31T08:45:20Z
date_updated: 2023-03-31T08:45:25Z
ddc:
- '660'
department:
- _id: '150'
- _id: '9'
file:
- access_level: closed
content_type: application/vnd.openxmlformats-officedocument.wordprocessingml.document
creator: torue
date_created: 2023-03-31T08:43:57Z
date_updated: 2023-03-31T08:43:57Z
file_id: '43239'
file_name: A_novel_method_for_determining_the_true_shear_rate_in_a_couette_rheometer.docx
file_size: 17099
relation: main_file
success: 1
file_date_updated: 2023-03-31T08:43:57Z
has_accepted_license: '1'
keyword:
- Couette
- Rheology
- Correction
language:
- iso: eng
status: public
title: A novel correction method for the shear rate in a couette rheometer (Vortrag)
type: conference_abstract
user_id: '76950'
year: '2022'
...
---
_id: '21949'
abstract:
- lang: eng
text: This paper presents the results of an interlaboratory study of the rheological
properties of cement paste and ultrasound gel as reference substance. The goal
was to quantify the comparability and reproducibility of measurements of the Bingham
parameters yield stress and plastic viscosity when measured on one specific paste
composition and one particular ultrasound gel in different laboratories using
different rheometers and measurement geometries. The procedures for both in preparing
the cement paste and carrying out the rheological measurements on cement paste
and ultrasound gel were carefully defined for all of the study’s participants.
Different conversion schemes for comparing the results obtained with the different
measurement setups are presented here and critically discussed. The procedure
proposed in this paper ensured a reasonable comparability of the results with
a coefficient of variation for the yield stress of 27% and for the plastic viscosity
of 24%, despite the individual measurement series’ having been performed in different
labs with different rheometers and measurement geometries.
article_type: original
author:
- first_name: Michael
full_name: Haist, Michael
last_name: Haist
- first_name: Julian
full_name: Link, Julian
last_name: Link
- first_name: David
full_name: Nicia, David
last_name: Nicia
- first_name: Sarah
full_name: Leinitz, Sarah
last_name: Leinitz
- first_name: Christian
full_name: Baumert, Christian
last_name: Baumert
- first_name: Tabea
full_name: von Bronk, Tabea
last_name: von Bronk
- first_name: Dario
full_name: Cotardo, Dario
last_name: Cotardo
- first_name: Mahmoud
full_name: Eslami Pirharati, Mahmoud
last_name: Eslami Pirharati
- first_name: Shirin
full_name: Fataei, Shirin
last_name: Fataei
- first_name: Harald
full_name: Garrecht, Harald
last_name: Garrecht
- first_name: Christoph
full_name: Gehlen, Christoph
last_name: Gehlen
- first_name: Inga
full_name: Hauschildt, Inga
last_name: Hauschildt
- first_name: Irina
full_name: Ivanova, Irina
last_name: Ivanova
- first_name: Steffen
full_name: Jesinghausen, Steffen
id: '3959'
last_name: Jesinghausen
orcid: https://orcid.org/0000-0003-2611-5298
- first_name: Christopher
full_name: Klein, Christopher
last_name: Klein
- first_name: Hans-W.
full_name: Krauss, Hans-W.
last_name: Krauss
- first_name: Ludger
full_name: Lohaus, Ludger
last_name: Lohaus
- first_name: Dirk
full_name: Lowke, Dirk
last_name: Lowke
- first_name: Oliver
full_name: Mazanec, Oliver
last_name: Mazanec
- first_name: Sebastian
full_name: Pawelczyk, Sebastian
last_name: Pawelczyk
- first_name: Ursula
full_name: Pott, Ursula
last_name: Pott
- first_name: Nonkululeko W.
full_name: Radebe, Nonkululeko W.
last_name: Radebe
- first_name: Joachim Jürgen
full_name: Riedmiller, Joachim Jürgen
last_name: Riedmiller
- first_name: Hans-Joachim
full_name: Schmid, Hans-Joachim
id: '464'
last_name: Schmid
- first_name: Wolfram
full_name: Schmidt, Wolfram
last_name: Schmidt
- first_name: Egor
full_name: Secrieru, Egor
last_name: Secrieru
- first_name: Dietmar
full_name: Stephan, Dietmar
last_name: Stephan
- first_name: Mareike
full_name: Thiedeitz, Mareike
last_name: Thiedeitz
- first_name: Manfred
full_name: Wilhelm, Manfred
last_name: Wilhelm
- first_name: Viktor
full_name: Mechtcherine, Viktor
last_name: Mechtcherine
citation:
ama: 'Haist M, Link J, Nicia D, et al. Interlaboratory study on rheological properties
of cement pastes and reference substances: comparability of measurements performed
with different rheometers and measurement geometries. Materials and Structures.
Published online 2020. doi:10.1617/s11527-020-01477-w'
apa: 'Haist, M., Link, J., Nicia, D., Leinitz, S., Baumert, C., von Bronk, T., Cotardo,
D., Eslami Pirharati, M., Fataei, S., Garrecht, H., Gehlen, C., Hauschildt, I.,
Ivanova, I., Jesinghausen, S., Klein, C., Krauss, H.-W., Lohaus, L., Lowke, D.,
Mazanec, O., … Mechtcherine, V. (2020). Interlaboratory study on rheological properties
of cement pastes and reference substances: comparability of measurements performed
with different rheometers and measurement geometries. Materials and Structures.
https://doi.org/10.1617/s11527-020-01477-w'
bibtex: '@article{Haist_Link_Nicia_Leinitz_Baumert_von Bronk_Cotardo_Eslami Pirharati_Fataei_Garrecht_et
al._2020, title={Interlaboratory study on rheological properties of cement pastes
and reference substances: comparability of measurements performed with different
rheometers and measurement geometries}, DOI={10.1617/s11527-020-01477-w},
journal={Materials and Structures}, author={Haist, Michael and Link, Julian and
Nicia, David and Leinitz, Sarah and Baumert, Christian and von Bronk, Tabea and
Cotardo, Dario and Eslami Pirharati, Mahmoud and Fataei, Shirin and Garrecht,
Harald and et al.}, year={2020} }'
chicago: 'Haist, Michael, Julian Link, David Nicia, Sarah Leinitz, Christian Baumert,
Tabea von Bronk, Dario Cotardo, et al. “Interlaboratory Study on Rheological Properties
of Cement Pastes and Reference Substances: Comparability of Measurements Performed
with Different Rheometers and Measurement Geometries.” Materials and Structures,
2020. https://doi.org/10.1617/s11527-020-01477-w.'
ieee: 'M. Haist et al., “Interlaboratory study on rheological properties
of cement pastes and reference substances: comparability of measurements performed
with different rheometers and measurement geometries,” Materials and Structures,
2020, doi: 10.1617/s11527-020-01477-w.'
mla: 'Haist, Michael, et al. “Interlaboratory Study on Rheological Properties of
Cement Pastes and Reference Substances: Comparability of Measurements Performed
with Different Rheometers and Measurement Geometries.” Materials and Structures,
2020, doi:10.1617/s11527-020-01477-w.'
short: M. Haist, J. Link, D. Nicia, S. Leinitz, C. Baumert, T. von Bronk, D. Cotardo,
M. Eslami Pirharati, S. Fataei, H. Garrecht, C. Gehlen, I. Hauschildt, I. Ivanova,
S. Jesinghausen, C. Klein, H.-W. Krauss, L. Lohaus, D. Lowke, O. Mazanec, S. Pawelczyk,
U. Pott, N.W. Radebe, J.J. Riedmiller, H.-J. Schmid, W. Schmidt, E. Secrieru,
D. Stephan, M. Thiedeitz, M. Wilhelm, V. Mechtcherine, Materials and Structures
(2020).
date_created: 2021-05-04T08:49:44Z
date_updated: 2023-01-17T07:42:21Z
department:
- _id: '150'
doi: 10.1617/s11527-020-01477-w
keyword:
- Rheology
- Wall Slip
- Slip
- apparent slip
- suspension
- cement
- concrete
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://link.springer.com/article/10.1617/s11527-020-01477-w
oa: '1'
publication: Materials and Structures
publication_identifier:
issn:
- 1359-5997
- 1871-6873
publication_status: published
quality_controlled: '1'
status: public
title: 'Interlaboratory study on rheological properties of cement pastes and reference
substances: comparability of measurements performed with different rheometers and
measurement geometries'
type: journal_article
user_id: '3959'
year: '2020'
...
---
_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'
...