How to determine harmonic number

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In summary, the conversation is about a project to make a PVC pipe instrument and finding the frequency of each pipe. The formula for open-ended instruments is provided, but the person is unsure about the harmonic numbers and how to determine them. The expert summarizer suggests using integers for Hn and explains that the fundamental frequency can be computed for each pipe using f=v/(2L). The conversation also discusses the concept of harmonics and how they are not determined by the length of the pipe. The expert summarizer suggests focusing on the fundamentals for each pipe to determine the note. A resource for learning more about harmonics is also recommended.
  • #1
Nickod777
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Homework Statement



I have 8 pipes for a school project taped together to make a pan flute, they are 7, 9, 11, 13, 15, 17, 19, 21 inches... 1 inch diameter each one. I have to find the frequency of each one, but I'm not sure what the Harmonic numbers are. It is an open-ended instrument. I plan to use as a percussion instrument, using my hand, hitting the ends of the pipe to create sound.

Homework Equations



F = Hn * V/2L
F: frequency
Hn: Harmonic number
V: speed of sound traveling through pipe assume 343 m/s
L: length of pipe sound is traveling through

The Attempt at a Solution



I'm not sure how, as I do not know how to find the harmonic number, my teacher just gave us a project to make a pvc pipe instrument and a formula for Open-ended, stringed, and closed instruments. The teacher does not expect questions on anything...

Not sure how to attempt without harmonic numbers...
 
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  • #2
I am not sure about what you are trying to do, but looking at that formula, I do not see a problem in just plugging integers to compute the frequencies for each pipe. Hn=1,2,3...
 
  • #3
I just don't know what Harmonic numbers are. I didn't know whether to make the smallest pipe 1 or the longest pipe 1.. I need to use that to figure out the frequency of each pipe so that I can then determine the note.

Sorry I can't really provide much information, but all I was looking for was a good explanation as to what harmonic numbers are. We don't have a textbook or anything in notes and such to explain harmonic numbers.

But I think I get it. longest pipe should be lowest number and smallest pipe longest number. Since the smaller it is, the higher the frequency I believe... (I don't know anything about notes, waves, harmonics, etc.)
 
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  • #4
Nickod777 said:
I just don't know what Harmonic numbers are. I didn't know whether to make the smallest pipe 1 or the longest pipe 1.. I need to use that to figure out the frequency of each pipe so that I can then determine the note.

Sorry I can't really provide much information, but all I was looking for was a good explanation as to what harmonic numbers are. We don't have a textbook or anything in notes and such to explain harmonic numbers.

But I think I get it. longest pipe should be lowest number and smallest pipe longest number. Since the smaller it is, the higher the frequency I believe... (I don't know anything about notes, waves, harmonics, etc.)
The harmonic numbers are 1,2,3... for all pipes they are not determined in any way on the length of the pipe. So you can compute the fundamental frequency i.e Hn=1 for each of the pipes just by using f=v/(2L). If you need the other harmonics just plug Hn=2,3,... For each pipe you get 1 fundamental and a series of harmonics.
 
  • #5
From each pipe you can get a fundamental note and, potentially, higher harmonics. From the OP, it seems to me that all you care about are the fundamentals, which you can compute from the formula you have, setting Hn=1. The length of each pipe dictates its fundamental and higher harmonics independently of the other pipes.
If you want to learn more about harmonics anyway, try http://www.physicsclassroom.com/Class/sound/u11l5c.cfm.
 

FAQ: How to determine harmonic number

1. What is a harmonic number?

A harmonic number is a number that is obtained by adding the reciprocals of the positive integers up to a certain limit. It is represented by the symbol Hn, where n is the limit.

2. How do you determine the value of a harmonic number?

The value of a harmonic number can be determined by using the formula Hn = 1 + 1/2 + 1/3 + 1/4 + ... + 1/n. This means that you add the reciprocals of all the positive integers up to the limit, and then add 1 to the result.

3. Can harmonic numbers be negative?

No, harmonic numbers cannot be negative. They are always positive or equal to zero.

4. What are some real-life applications of harmonic numbers?

Harmonic numbers have various applications in fields such as physics, engineering, and finance. They are used to calculate the average of ratios, calculate electrical networks, and estimate probabilities in statistics, among other things.

5. How can harmonic numbers be calculated using a computer program?

Harmonic numbers can be calculated using a computer program by using a loop to add the reciprocals of the positive integers up to the limit, and then adding 1 to the result. The limit can be entered by the user or set as a constant in the program. Alternatively, there are also pre-made functions and algorithms available for calculating harmonic numbers in programming languages such as Python and Java.

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