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<p> Aircraft engines require lightweight
efficient thermal management devices to improve engine performance at high
pressure ratios. Acoustic streaming can provide a viable, lightweight solution
to improve the heat exchanger capacity with a reduced drag penalty within
engine heat exchangers. This project develops a test section that will
experimentally characterize the effect of acoustic streaming on the unsteady
heat flux and shear stress within a narrow channel. This is accomplished by
careful selection of measurement techniques to monitor the steady and unsteady
properties of the flow and iteratively designing the test section with CFD
support to converge to an optimal test model. Using CFD support to revise each
iteration reduces the experimental cost of developing an effective geometry. </p>
<p> Pressure taps and K-type
thermocouples are used to monitor the total inlet pressure and temperature as
well as the wall surface pressure and temperature. Optical shear stress sensors
are selected to monitor the unsteady wall shear stress. A thin film sensor
array is designed for high frequency wall temperature measurements which serve
the boundary condition for a 1-D heat flux analysis to determine the unsteady
heat flux through the wall. The test model consists of two hollow Teflon
airfoils that create a narrow channel within a larger flow area. The airfoils
create three flow paths within the wind tunnel test section and the area ratio
between the measured flow and the bypass flow controls the Mach number of
within the measured flow channel. The acoustic waves drive acoustic streaming and
are generated by a Rossiter Cavity with L/D =2 which produces pressure
oscillations with dominant frequency of 8 kHz in a Mach 0.8 flow. </p>
<p> The test geometry successfully
achieves <a>Mach
0.8 flow and the 8 kHz signal </a><a href="https://purdue0-my.sharepoint.com/personal/mbutzen_purdue_edu/Documents/MS Thesis/Thesis Living Document.docx#_msocom_1">[BMJW1]</a> from the Rossiter cavity. The successful commissioning
sets the stage for future experiments to determine the potential of acoustic
streaming as a low weight modification to improve compact heat exchangers. </p>
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| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/15078447 |
| Date | 29 July 2021 |
| Creators | Michael John Willi Butzen (8877470) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/thesis/Design_of_Test_Section_for_Modulating_Heat_Flux_Using_Acoustic_Streaming_in_Narrow_Channel_Experiments/15078447 |
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