Designing a resonance tube with a defined ambient wind speed

In summary: The original paper is a German-language article about organ pipes. It's not about the same situation as you have, but here is a brief summary in English:If you are trying to design a wind instrument, you need to know the pressure and air consumption rate at the open end of the instrument, and the pressure and air consumption rate at the bottom of the instrument. You can find this information by measuring the pressure and air consumption rate at the open end of the instrument and the pressure and air consumption rate at the bottom of the instrument.
  • #1
AuroraIndust
11
0
Hello,

As we know, when you blow over the neck of a bottle, it resonates at a certain frequency.

I want to build a cylinder that will resonate at a certain wind speed: 4 mph or about 1.78 m/s

I definitely know how to find the resonant frequency of a cylinder. However, I'm not sure what equation would help me solve for finding what "wind speed" over the top would cause it to resonate!

What am I missing here? Is this a more difficult problem than I anticipate?

Thanks!
 
Physics news on Phys.org
  • #2
People have been designing wind instruments empirically for thousands of years, but it seems that a theory of what works and what doesn't was first published only in 1971!

The original paper is in German and is about organ pipes, so the geometry isn't exactly the same as your situation, but here's a reference to a (very short) summary in English: http://www.mmdigest.com/Tech/isingform.html

If you investigate how well this works for bottles, you will probably be doing some genuinely original research.
 
  • #3
Do you know what Q, the "Air consumption rate" might be referring to? I don't see where any air is being "consumed".

I can find the pressure of the air at the open end of the cylinder, and I know the pressure at the bottom of the cylinder. Assuming I know those and several other things I should be able to calculate what size/volume tube will work, right?

If someone can assist me in adapting this (http://www.mmdigest.com/Tech/isingform.html) to work with my situation, that would be much appreciated. As I can not figure out a way...

Thanks for any help!
 
  • #4
An organ pipe (or a recorder, for that matter) needs air blown into it: Thats your air consumption rate.
Are thinking of something like a a pan flute?
You can find a lot of information and details in Fletcher/Rossing, The physics of musical instruments.
And if my experience with instruments is not totally off: I don´t think you can make a speed detector out of a flute, and 2m/sec is far too slow.
Recorders need a blowing pressure of a few cm water gauge; organs are nearer to 10cm. (Transverse) flutes are not much different.
1cm water gauge = 100Pa => ~13m/sec

In the link, Walcker is a german organ builder and Hausmitteilung is "internal communication". I´m sure you can find the articles by Ising elswhere
 
  • #5


Hello there,

Designing a resonance tube with a defined ambient wind speed can be a challenging task. The resonant frequency of a cylinder is determined by its length, cross-sectional area, and the speed of sound in the medium it is in. However, in order to determine the wind speed that would cause the cylinder to resonate, we would need to consider additional factors such as the density and viscosity of the surrounding air. This can make the problem more complex than just finding the resonant frequency.

One approach to solving this problem would be to use fluid dynamics equations and principles to model the flow of air over the cylinder and determine the wind speed at which resonance would occur. This would require a thorough understanding of fluid mechanics and may require computational simulations or experiments to accurately determine the wind speed.

Another approach could be to experimentally determine the wind speed that causes resonance by varying the wind speed and measuring the resulting resonant frequency. This would require precise measurements and careful control of the wind speed.

Overall, designing a resonance tube with a defined ambient wind speed may not be a straightforward task and may require a combination of theoretical and experimental approaches. I hope this helps guide you in finding a solution to your problem. Best of luck!
 

1. How does ambient wind speed affect the resonance tube design?

The ambient wind speed plays a crucial role in the design of a resonance tube. It affects the length and diameter of the tube, as well as the position of the sound source and microphone. A higher wind speed may require a longer and wider tube to achieve the desired resonance frequency.

2. What is the ideal wind speed for designing a resonance tube?

The ideal wind speed for designing a resonance tube depends on the desired resonance frequency. Generally, a low wind speed of 5-10 mph is recommended for most applications. However, for higher resonance frequencies, a higher wind speed may be required.

3. How do I determine the length and diameter of the resonance tube for a specific wind speed?

To determine the length and diameter of the resonance tube, you can use the formula: L = (n * λ) / 2, where L is the length of the tube, n is the desired resonance mode, and λ is the wavelength of the sound produced by the source. The diameter of the tube can be calculated using the formula: D = λ / 4, where D is the diameter of the tube.

4. Can I use a fan to control the ambient wind speed for the resonance tube?

Yes, a fan can be used to control the ambient wind speed for the resonance tube. It is important to use a fan with adjustable speed settings to achieve the desired wind speed. It is also recommended to place the fan at a distance from the tube to avoid any interference with the sound produced.

5. How can I measure the ambient wind speed for my resonance tube design?

The ambient wind speed can be measured using an anemometer, which is a device specifically designed to measure wind speed. Alternatively, you can use a smartphone app that has an anemometer feature. It is important to take multiple measurements at different points around the tube to get an accurate average wind speed.

Similar threads

  • Mechanics
Replies
11
Views
1K
  • Mechanical Engineering
2
Replies
40
Views
3K
Replies
9
Views
2K
Replies
6
Views
1K
  • Electrical Engineering
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
12
Views
3K
Replies
9
Views
2K
  • Classical Physics
Replies
10
Views
4K
Replies
35
Views
7K
Replies
3
Views
926
Back
Top