scholarly journals Calibration Routine for Quantitative Three-Dimensional Flow Field Measurements in Drying Polymer Solutions Subject to Marangoni Convection

2019 ◽  
Vol 3 (1) ◽  
pp. 39
Author(s):  
Max Tönsmann ◽  
Fabian Kröhl ◽  
Philipp Cavadini ◽  
Philip Scharfer ◽  
Wilhelm Schabel
Keyword(s):  
Flow Field ◽  
Particle Tracking Velocimetry ◽  
Transient Flow ◽  
Marangoni Convection ◽  
Three Dimensional ◽  
Field Measurements ◽  
Calibration Procedure ◽  
Cover Glass ◽  
Spread Function ◽  
Multifocal Lens

Surface-tension induced flows may have a significant impact on the surface topography of thin films or small printed structures derived from polymer solution processing. Despite a century of research on Marangoni convection, the community lacks quantitative experimental flow field data, especially from within drying solutions. We utilize multifocal micro particle tracking velocimetry (µPTV) to obtain these data and show a calibration routine based on point spread function (PSF) simulations as well as experimental data. The results account for a varying sample refractive index, beneficial cover-glass correction collar settings as well as a multifocal lens system. Finally, the calibration procedure is utilized exemplarily to reconstruct a three-dimensional, transient flow field within a poly(vinyl acetate)-methanol solution dried with inhomogeneous boundary conditions.

scholarly journals Measurement of Lagrangian Trajectories in a 3 L Stirred Tank Reactor using 4D Particle Tracking Velocimetry with Shake-the-Box

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Jürgen Fitschen ◽  
Alexandra Von Kameke ◽  
Sebastian Hofmann ◽  
Marko Hoffmann ◽  
Michael Schlüter
Keyword(s):  
Flow Field ◽  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Three Dimensional ◽  
Field Measurements ◽  
Stirred Tank ◽  
Two Dimensional ◽  
Scientific Publications ◽  
Stirred Tank Reactor ◽  
Tank Reactor

Stirred tank reactors are widely used in the chemical industry and bioprocess engineering and, consequently, a large number of scientific publications deal with the characterization of those apparatuses. However, there is very little information about the flow conditions. This is mostly due to the fact that these apparatuses are generally made of stainless steel, which restricts optical access. Furthermore, three-dimensional flow field measurements are still not trivial and involve costly equipment, therefore, investigations often reduce to two-dimensional PIV measurements. Nevertheless, recent works (Rosseburg et al., 2018; Taghavi and Moghaddas, 2020; Kuschel et al., 2021) impressively show the formation of compartments which hinder and delay mixing. However, these measurements are based either on instantaneous concentration profiles by means of pLIF measurements or on a two-dimensional projection of the system and thus do not allow conclusions about the development of the three dimensional compartments and the exchange rates between the compartments. In this work, for the first time, instantaneous flow field measurements with high spatial and temporal resolution are performed in the entire volume of a 3L stirred tank reactor based on 4D particle tracking velocimetry. The highly resolved particle trajectories further allow detailed Lagrangian analysis of the mixing dynamics inside the reactor, data that was previously inaccessible.

scholarly journals Transient Three-Dimensional Flow Field Measurements by Means of 3D µPTV in Drying Poly(Vinyl Acetate)-Methanol Thin Films Subject to Short-Scale Marangoni Instabilities

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1223
Author(s):  
Max Tönsmann ◽  
Philip Scharfer ◽  
Wilhelm Schabel
Keyword(s):  
Flow Field ◽  
Vinyl Acetate ◽  
Three Dimensional ◽  
Field Measurements ◽  
Initial Assessment ◽  
Ambient Conditions ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Short Scale ◽  
Dry Film

Convective Marangoni instabilities in drying polymer films may induce surface deformations, which persist in the dry film, deteriorating product performance. While theoretic stability analyses are abundantly available, experimental data are scarce. We report transient three-dimensional flow field measurements in thin poly(vinyl acetate)-methanol films, drying under ambient conditions with several films exhibiting short-scale Marangoni convection cells. An initial assessment of the upper limit of thermal and solutal Marangoni numbers reveals that the solutal effect is likely to be the dominant cause for the observed instabilities.

Three-dimensional flow-field measurements in multistage turbomachinery using a computer-aided system

1997 ◽  
Author(s):  
Antoni Smolny ◽  
Jaroslaw Blaszczak ◽  
Ryszard Pawlak
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Field Measurements ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Computer Aided

scholarly journals Assessment of the Flow Field in the HeartMate 3 Using Three-Dimensional Particle Tracking Velocimetry and Comparison to Computational Fluid Dynamics

ASAIO Journal ◽  
2020 ◽  
Vol 66 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Bente Thamsen ◽  
Utku Gülan ◽  
Lena Wiegmann ◽  
Christian Loosli ◽  
Marianne Schmid Daners ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Flow Field ◽  
Particle Tracking ◽  
Particle Tracking Velocimetry ◽  
Three Dimensional

scholarly journals Comparative Study on CFD Turbulence Models for the Flow Field in Air Cooled Radiator

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1687
Author(s):  
Chao Yu ◽  
Xiangyao Xue ◽  
Kui Shi ◽  
Mingzhen Shao ◽  
Yang Liu
Keyword(s):  
Flow Field ◽  
Transient Flow ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Compartment Model ◽  
Navier Stokes ◽  
Engine Compartment ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Relevant Calculation

This paper compares the performances of three Computational Fluid Dynamics (CFD) turbulence models, Reynolds Average Navier-Stokes (RANS), Detached Eddy Simulation (DES), and Large Eddy Simulation (LES), for simulating the flow field of a wheel loader engine compartment. The distributions of pressure fields, velocity fields, and vortex structures in a hybrid-grided engine compartment model are analyzed. The result reveals that the LES and DES can capture the detachment and breakage of the trailing edge more abundantly and meticulously than RANS. Additionally, by comparing the relevant calculation time, the feasibility of the DES model is proved to simulate the three-dimensional unsteady flow of engine compartment efficiently and accurately. This paper aims to provide a guiding idea for simulating the transient flow field in the engine compartment, which could serve as a theoretical basis for optimizing and improving the layout of the components of the engine compartment.

Three-dimensional flow field measurements using LDV in the exit region of a radial inflow turbine

1996 ◽  
Vol 21 (1) ◽  
pp. 1-10 ◽  
Author(s):  
D. M. Murugan ◽  
W. Tabakoff ◽  
A. Hamed
Keyword(s):  
Flow Field ◽  
Three Dimensional ◽  
Field Measurements ◽  
Three Dimensional Flow ◽  
Exit Region ◽  
Dimensional Flow ◽  
Radial Inflow Turbine

Blade Row Interaction in a One and a Half Stage Transonic Turbine Focusing on Three Dimensional Effects: Part II—Clocking Effects

2008 ◽  
Author(s):  
O. Schennach ◽  
B. Paradiso ◽  
G. Persico ◽  
P. Gaetani ◽  
J. Woisetschla¨ger
Keyword(s):  
High Pressure ◽  
Flow Field ◽  
Three Dimensional ◽  
Field Measurements ◽  
Fast Response ◽  
Secondary Flows ◽  
Pressure Probe ◽  
Flow Angle ◽  
Aerodynamic Pressure ◽  
Transonic Turbine

The paper presents an experimental investigation of the flow field in a high-pressure transonic turbine with a downstream vane row (1.5 stage machine) concerning the airfoil indexing. The objective is a detailed analysis of the three dimensional flow field downstream of the high pressure turbine for different vane clocking positions. To give an overview of the time averaged flow field, measurements by means of a pneumatic five hole probe were performed upstream and downstream of the second stator. Furthermore in this planes additional unsteady measurements were carried out with Laser Doppler Velocimetry in order to record rotor phase resolved velocity, flow angle and turbulence distributions at two different clocking positions. In the measurement plane upstream the second vane the time resolved pressure field has been analyzed by means of a Fast Response Aerodynamic Pressure Probe. The paper shows that the secondary flows of the second vane are significantly modified for different clocking positions, in connection with the first vane modulation of the rotor secondary flows. An analysis of the performance of the second vane is also carried out.

Numerical and experimental investigation of a low-pressure steam turbine during windage

2009 ◽  
Vol 223 (6) ◽  
pp. 697-708 ◽  
Author(s):  
R Sigg ◽  
C Heinz ◽  
M V Casey ◽  
N Sürken
Keyword(s):  
Flow Field ◽  
Steam Turbine ◽  
Power Plants ◽  
Pressure Ratio ◽  
Three Dimensional ◽  
Field Measurements ◽  
Low Pressure ◽  
Output Pressure ◽  
Ansys Cfx ◽  
Lp Turbine

Modern steam power plants must operate safely at extremely low loads, known as windage, in which the low pressure (LP) turbine runs with decreased or even zero flow. Windage is characterized by a strongly unsteady three-dimensional (3D) flow field leading to possible aerodynamic excitations. Extensive flow field measurements were performed in an LP steam turbine test rig during windage, using pneumatic probes in the last stage and a diffuser. The flow field of the whole turbine was also calculated with steady 3D computational fluid dynamics (ANSYS CFX). Good agreement is found between the simulations and the measurements of the flow field, and the characteristic vortex structures behind the last rotor row are captured. The numerically predicted trends of power output, pressure ratio, and temperature of the last turbine blade row closely match the experimental data. The complex vortex flow in the stage is interpreted using both numerical and experimental results.

Three-Dimensional Flow Field Measurements in a Radial Inflow Turbine Scroll Using LDV

1987 ◽  
Vol 109 (2) ◽  
pp. 163-169 ◽  
Author(s):  
M. F. Malak ◽  
A. Hamed ◽  
W. Tabakoff
Keyword(s):  
Experimental Study ◽  
Flow Field ◽  
Flow Velocity ◽  
Three Dimensional ◽  
Field Measurements ◽  
Three Dimensional Flow ◽  
Cold Flow ◽  
Dimensional Flow ◽  
Through Flow ◽  
Radial Inflow Turbine

The results of an experimental study of the three-dimensional flow field in a radial inflow turbine scroll are presented. A two-color LDV system was used in the measurement of three orthogonal velocity components at 758 points located throughout the scroll and the unvaned portion of the nozzle. The cold flow experimental results are presented for through-flow velocity contours and the cross velocity vectors.

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