EXP 1-4 Experimental Set Up: Difference between revisions

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=Axisymmetric drop impact dynamics on a wall film of the same liquid=
=Axisymmetric drop impact dynamics on a wall film of the same liquid=
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= Experimental Setup=
= Experimental Setup=
''Describe briefly the test facility and the measurement procedure''


The experimental setup can be divided into three
The experimental setup shown in Fig. 3 can be divided into three
main units including the drop generator, the impact substrate and the
main units including the drop generator, the impact substrate and the
observation system.
observation system.  


The '''drop generator''' is based on a drop on demand method. A micropump
* The '''drop generator''' is based on a drop on demand method. A micropump transports the liquid from a tank to the cannula. The drop drips off the cannula tip by gravity as soon as the critical mass is reached. A vertical tube reduces the influence of the air flow in the room on the trajectory of the falling drop, so that the point of impact remains reproducible. The impact velocity of the drop is varied by altering the height of the cannula tip relative to the liquid film interface.  
transports the liquid from a tank to the cannula. The drop drips off
the cannula tip by gravity as soon as the critical mass is reached. The
* The '''impact substrate''' is an aluminum block with a recess of 70 mm diameter and 0.6 mm depth. The recess constrains the liquid so that films with a defined film thickness can be placed. The film thickness is measured by a chromatic line Sensor (Precitec CHRocodile CLS) which allows measuring the film thickness on 192 points aligned on a line of 1 mm length, to assure uniform film thickness.  
impact velocity of the drop is varied by altering the height of the cannula
 
tip relative to the liquid film interface. The '''impact substrate''' is an
* The '''observation system''' is described in [[EXP 1-4 Measurement Quantities and Techniques]]. There, also a suitable setup for CFD calculations is given.
aluminium block with a recess of 70 mm diameter and 0.6 mm depth.
 
The recess constrains the liquid so that films with a defined film thickness
 
can be placed. The film thickness is measured by a chromatic line Sensor (Precitec
[[File:TRR150-Fig-Setup.png|400px|thumb|center|Fig. 3: Schematic representation of the experimental setup.]]
CHRocodile CLS) which allows measuring the film thickness on 192
points aligned on a line of 1 mm length, to assure uniform film thickness.


Images are taken with a high-speed CMOS camera (Photron SA-X2),
recording the impact at a frame rate of 20000 fps with a magnification of
31 μm/px. A synchronized high-performance LED (Constellation 120E)
in combination with a diffuser plate provides a uniform background
illumination. When carrying out the experiments, a uniform film of 500
μm thickness is prepared utilizing the film thickness sensor. In the next
step, the film thickness sensor is moved and a drop is generated. Shadowgraph
images are taken during the drop impact onto the liquid film.


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{{ACContribs
{{ACContribs
|authors=Bastian Stumpf, Milad Bagheri, Ilia V. Roisman, Cameron Tropea, Jeanette Hussong, Martin Wörner, Holger Marschall
|authors=Milad Bagheri, Bastian Stumpf, Ilia V. Roisman, Cameron Tropea, Jeanette Hussong, Martin Wörner, Holger Marschall
|organisation=Technical University of Darmstadt and Karlsruhe Institute of Technology
|organisation=Technical University of Darmstadt and Karlsruhe Institute of Technology
}}
}}
{{EXPHeaderLib
{{EXPHeader
|area=1
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Latest revision as of 10:01, 17 August 2023

Axisymmetric drop impact dynamics on a wall film of the same liquid

Front Page

Introduction

Review of experimental studies

Description

Experimental Set Up

Measurement Quantities and Techniques

Data Quality and Accuracy

Measurement Data and Results

Experimental Setup

The experimental setup shown in Fig. 3 can be divided into three main units including the drop generator, the impact substrate and the observation system.

  • The drop generator is based on a drop on demand method. A micropump transports the liquid from a tank to the cannula. The drop drips off the cannula tip by gravity as soon as the critical mass is reached. A vertical tube reduces the influence of the air flow in the room on the trajectory of the falling drop, so that the point of impact remains reproducible. The impact velocity of the drop is varied by altering the height of the cannula tip relative to the liquid film interface.
  • The impact substrate is an aluminum block with a recess of 70 mm diameter and 0.6 mm depth. The recess constrains the liquid so that films with a defined film thickness can be placed. The film thickness is measured by a chromatic line Sensor (Precitec CHRocodile CLS) which allows measuring the film thickness on 192 points aligned on a line of 1 mm length, to assure uniform film thickness.


Fig. 3: Schematic representation of the experimental setup.





Contributed by: Milad Bagheri, Bastian Stumpf, Ilia V. Roisman, Cameron Tropea, Jeanette Hussong, Martin Wörner, Holger Marschall — Technical University of Darmstadt and Karlsruhe Institute of Technology

Front Page

Introduction

Review of experimental studies

Description

Experimental Set Up

Measurement Quantities and Techniques

Data Quality and Accuracy

Measurement Data and Results


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