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JaredJHuffman
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Could the principle of Edge Tone used to create a frequency in the airflow of a musical instrument such as the recorder be used to impart a frequency on a much larger air stream? Ideally I would use it in something in the range of a 24" diameter fan with around 130 mph velocity and approximately 1000 cfm. My goal would be around 85 Hz.
I'm a machine design engineer and am new to the airflow side of things, so please be patient with me. Here's my best understanding:
The easiest way to visualize this is to consider the mouthpiece of a recorder. Air is moved at a constant speed through a slit. An edge splits the airstream which generates eddy currents in a certain frequency on both sides of the edge at 180 degrees offset from each other. Either increasing the air speed or moving the edge closer to the slit will increase the frequency. Here's one explanation (http://hyperphysics.phy-astr.gsu.edu/hbase/music/edge3.html#c2"). It works differently inside of a pipe than without one (nodes can be created by opening or closing the holes), but the principle of how the original frequency is generated is the same.
Here are a couple videos showing the http://www.cfd.tu-berlin.de/%7Epanek/cfd/EdgeTone04.mpg" . Does this effect require a slit as the source, or would it work with an edge over a round airstream?
What is the effect of the edge on the velocity of the airflow?
How does the thickness of the edge effect the direction and frequency of the stream?
Would this work on a large scale as discussed in my introduction?Thanks so much for the help!
-Jared J Huffman
I'm a machine design engineer and am new to the airflow side of things, so please be patient with me. Here's my best understanding:
The easiest way to visualize this is to consider the mouthpiece of a recorder. Air is moved at a constant speed through a slit. An edge splits the airstream which generates eddy currents in a certain frequency on both sides of the edge at 180 degrees offset from each other. Either increasing the air speed or moving the edge closer to the slit will increase the frequency. Here's one explanation (http://hyperphysics.phy-astr.gsu.edu/hbase/music/edge3.html#c2"). It works differently inside of a pipe than without one (nodes can be created by opening or closing the holes), but the principle of how the original frequency is generated is the same.
Here are a couple videos showing the http://www.cfd.tu-berlin.de/%7Epanek/cfd/EdgeTone04.mpg" . Does this effect require a slit as the source, or would it work with an edge over a round airstream?
What is the effect of the edge on the velocity of the airflow?
How does the thickness of the edge effect the direction and frequency of the stream?
Would this work on a large scale as discussed in my introduction?Thanks so much for the help!
-Jared J Huffman
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