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Delegates of the national rheological societies
Society's Site Sep 2012 - Feb 2013
Appl. Rheol. 22:4 (2012) 214-220
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► Cite this publication as follows:
Rheological Societies: Society's Site Sep 2012 - Feb 2013, Appl. Rheol. 22 (2012) 214.
Christian Wagner
Joint Focus Session Rheology of the German Rheological Society (DRG) together with the German Physical Society (DPG)
Appl. Rheol. 22:4 (2012) 213-213
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► Cite this publication as follows:
Wagner C: Joint Focus Session Rheology of the German Rheological Society (DRG) together with the German Physical Society (DPG), Appl. Rheol. 22 (2012) 213.
Samsun Nahar, Shaik A. K. Jeelani, Erich J. Windhab
Peristaltic flow characterization of a shear thinning fluid through an elastic tube by UVP
Appl. Rheol. 22:4 (2012) 43941 (8 pages)
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In-vitro small intestinal flow characteristics of a shear thinning fluid are investigated by transient '2-wave'-squeezing of an
elastic tube under different speeds of peristalsis. Such peristaltic flow is the essential physiological transport mechanism in
the gastro-intestinal tract. The peristalsis involves both expansion and contraction type of flow (crest and trough of a wavelength).
We met the challenge of implementing the UVP technique for monitoring the velocity fields during appropriate peristaltic
propulsion of a shear thinning fluid through an elastic tube (in vitro modeled small intestine). The higher wave speed
of peristalsis results in higher magnitude of back flow velocity (negative) both in the wave crest and trough regions with positive
value being adjacent to the tube wall. In addition, the approximated wall shear rates at the wave trough are also found
to be higher than those in the wave crest. The higher value of back flow is expected to be responsible for the improved mixing
and convection leading to higher mass transport through the intestinal wall. The measured pressure difference between
crest and trough of a peristaltic wave increased, as the wave speed got faster. However, the crest region showed a higher pressure
compared to the trough region since the magnitude of back flow velocity in the wave trough is found to be much higher
compared to that in the wave crest.
► Cite this publication as follows:
Nahar S, Jeelani SAK, Windhab EJ: Peristaltic flow characterization of a shear thinning fluid through an elastic tube by UVP, Appl. Rheol. 22 (2012) 43941.
Reinhardt Kotze, Johan Wiklund, Rainer Haldenwang
Optimization of the UVP+PD rheometric method for flow behavior monitoring of industrial fluid suspensions
Appl. Rheol. 22:4 (2012) 42760 (11 pages)
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Ultrasonic Velocity Profiling (UVP) is a powerful technique for velocity profile measurements in research and engineering
applications as it is the only available method that is cost-effective, relatively easy to implement and applicable to opaque
fluid suspensions, which are frequently found in industry. UVP can also be combined with Pressure Drop (PD) measurements
in order to obtain rheological parameters of non-Newtonian fluids by fitting theoretical rheological models to a single velocity
profile measurement. The flow properties of complex fluids are almost exclusively obtained today using commercially
available instruments, such as conventional rotational rheometers or tube (capillary) viscometers. Since these methods are
time-consuming and unsuitable for real-time process monitoring, the UVP+PD methodology becomes a very attractive alternative
for in-line flow behavior monitoring as well as quality control in industrial applications. However, the accuracy of the
UVP+PD methodology is highly dependent on the shape and magnitude of the measured velocity profiles and there are still
a few problems remaining with current instrumentation and methods in order to achieve the robustness and accuracy
required in industrial applications. The main objective of this research work was to optimize an UVP+PD system by implementing
new transducer technology and signal processing techniques for more accurate velocity profile measurements as
well as rheological characterization of complex fluids under industrial/realistic conditions. The new methodology was evaluated
in two different pipe diameters (22.5 and 52.8 mm) and tested with three different non-Newtonian fluids in order to
obtain a wide range of rheological parameters. Results were also compared to conventional rotational rheometry and tube
viscometry. It was found that rheological parameters obtained from accurate velocity data across the pipe radius, especially
close to pipe walls where the velocity gradient is high, showed better agreement to conventional rheometry than when compared
to results obtained using profiles measured with conventional UVP instrumentation and commercial software (Met-
Flow SA Version 3.0). The UVP+PD method is now more robust and accurate. The main challenge remaining is to successfully
implement a complete non-invasive system in industrial processes that is able to achieve real-time and accurate complex
flow monitoring of non-Newtonian fluid suspensions.
► Cite this publication as follows:
Kotze R, Wiklund J, Haldenwang R: Optimization of the UVP+PD rheometric method for flow behavior monitoring of industrial fluid suspensions, Appl. Rheol. 22 (2012) 42760.
Beat Birkhofer, Alban Debacker, Simone Russo, Stefano Ricci, Didier Lootens
In-line rheometry based on ultrasonic velocity profiles: comparison of data processing methods
Appl. Rheol. 22:4 (2012) 44701 (9 pages)
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Ultrasonic Velocity Profiling with Pressure Drop (UVP+PD) is a technique, which allows the measurement of the shear rate
dependent viscosity non-invasively in a laminar pipe flow. To assess the performance of different data processing approaches
for the extraction of the rheometric values, model fluids are characterized under well defined flow conditions created with
a piston setup. Considering the shear rate range available in the pipe flow, a good quantitative agreement is found between
the in-line measurements and the off-line measurements made with a rotational rheometer
► Cite this publication as follows:
Birkhofer B, Debacker A, Russo S, Ricci S, Lootens D: In-line rheometry based on ultrasonic velocity profiles: comparison of data processing methods, Appl. Rheol. 22 (2012) 44701.
Johan Wiklund, Mashuqur Rahman, Ulf Hakansson
In-line rheometry of micro cement based grouts . a promising new industrial application of the ultrasound based UVP+PD method
Appl. Rheol. 22:4 (2012) 42783 (11 pages)
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Measurements of the viscosity of non-Newtonian fluids and suspensions having a solid volume fraction of about 30% or
more is of major interest from an industrial point of view. Cement paste and cement grouts for injection grouting applications,
with water to cement ratios typically in the range of 0.4 and 0.6 - 0.8 by weight, are two examples of industrial fluid
systems. Few in-line techniques are available on the market that can be used for these fluid systems and under realistic field
conditions. The so-called UVP+PD in-line rheometry method combining the Ultrasound Velocity Profiling (UVP) technique
with Pressure Difference (PD) measurements is a promising new tool for industrial applications. This paper presents an initial
pre-study that aims to demonstrate the feasibility of the UVP+PD method using cement grouts for process monitoring and
control of grouting applications under realistic field conditions. The UVP+PD method was tested and found successful for
continuous in-line measurements of concentrated micro cement-based grouts with water/cement ratios of 0.6 and 0.8. The
test set-up consisted of a combination of an experimental .flow loop. and a conventional field grouting rig - UNIGROUT, from
Atlas Copco. The rheological properties were determined, directly in-line and the parameters obtained were subsequently
compared with off-line measurements using a conventional rotational rheometer.
► Cite this publication as follows:
Wiklund J, Rahman M, Hakansson U: In-line rheometry of micro cement based grouts . a promising new industrial application of the ultrasound based UVP+PD method, Appl. Rheol. 22 (2012) 42783.
Johan Wiklund, Beat Birkhofer, SAK Jeelani, Mats Stading, Erich J. Windhab
In-line rheometry of particulate suspensions by pulsed ultrasound velocimetry combined with pressure difference method
Appl. Rheol. 22:4 (2012) 42232 (10 pages)
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The in-line rheometer concept based on the combination of the ultrasonic velocity profiling (UVP) technique and
pressure difference (PD) measurements was utilized for investigating the influence of particle concentration
and size distribution on the rheology of particulate suspensions in pipe flow under realistic industrial process
conditions. Well defined model suspensions were used, consisting of 11 mm and 90 mm diameter polyamide particles
suspended in rapeseed oil at concentrations ranging from 1 to 25 % by volume. The variation of concentration
and particle size distribution had the expected effects on the shear viscositiy of the investigated unimodal
and bimodal suspensions. The in-line results showed that the investigated suspensions exhibit Sisko flow
behavior and demonstrated that the UVP+PD method can be used to determine the flow behavior of complex
fluids and suspensions, even at high solid concentrations, under industrial conditions in-line. The obtained inline
results were in good agreement with measurement data obtained using a conventional rotational controlled-
stress rheometer. Limitations of commercially available transducer technology were identified and other
possible sources of inaccuracy of the UVP+PD method were investigated. Several improvements of the UVP+PD
measurement method were proposed.
► Cite this publication as follows:
Wiklund J, Birkhofer B, Jeelani S, Stading M, Windhab EJ: In-line rheometry of particulate suspensions by pulsed ultrasound velocimetry combined with pressure difference method, Appl. Rheol. 22 (2012) 42232.
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