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5 gallon musical water bottle
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Glenn Sowell
science forum beginner


Joined: 02 Jul 2006
Posts: 9

PostPosted: Tue Jul 04, 2006 12:08 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

In article <44a8d82b.15035921@text.usenet.plus.net>, Don Pearce
<nospam@nospam.com> wrote:

Quote:
On Sun, 02 Jul 2006 09:22:07 -0500, Glenn Sowell <sowell2@cox.net
wrote:

I want to make a set of musical water bottles using the typical 5
gallon bottles found on water coolers.

I can excite a REALLY low note by blowing air from a vacuum cleaner
across the top. Unfortunately, I also excite several overtones as well.


How can I excite just the fundamental? Slower moving air? By shaping
the vacuum attachment through which is blown?

Any pointers will be appreciated.

Glenn

You can't. And why would you want to? All of the quality of the sound
lies in those overtones. If you excited just the fundamentals you
would have sine waves, and not only are they very unmusical, but there
are much easier ways to make them then by blowing over bottles.

Having said all that, those plastic bottles aren't very stiff - they
vibrate strongly when you excite them that way and that absorbs much
of the sound energy. If you could get hold of stiffer bottles, like
the carboys that liquid chemicals come in, you would be able to
deliver a much more powerful sound.

d
You are right, of course. But the notes are accompained by high-pitched

squeals. Those I don't want.

The plastic bottles do vibrate strongly, but that does not stop 2-liter
pop bottles from working nicely.

Thanks
Glenn
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Glenn Sowell
science forum beginner


Joined: 02 Jul 2006
Posts: 9

PostPosted: Tue Jul 04, 2006 12:10 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

The wind driven instruments look very interesting. Thanks for the links.

Glenn

In article <1151934758.227415.57340@h44g2000cwa.googlegroups.com>,
<woinem1@aol.com> wrote:

Quote:
Don Pearce schrieb:

On Sun, 02 Jul 2006 09:22:07 -0500, Glenn Sowell <sowell2@cox.net
wrote:

I want to make a set of musical water bottles using the typical 5
gallon bottles found on water coolers.

I can excite a REALLY low note by blowing air from a vacuum cleaner
across the top. Unfortunately, I also excite several overtones as well.


How can I excite just the fundamental? Slower moving air? By shaping
the vacuum attachment through which is blown?

You might find some answers here:
http://members.aol.com/woinem1/index/physik.htm
and
http://perso.nnx.com/dferment/ukplasto.htm
We play with winddriven instruments since years now.
Have fun
Uli
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Mike Amling
science forum Guru


Joined: 05 May 2005
Posts: 525

PostPosted: Tue Jul 04, 2006 12:11 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

On Tue, 04 Jul 2006 07:08:36 -0500, Glenn Sowell <sowell2@cox.net>
wrote:

Quote:
You are right, of course. But the notes are accompained by high-pitched
squeals. Those I don't want.

The plastic bottles do vibrate strongly, but that does not stop 2-liter
pop bottles from working nicely.

Thanks
Glenn

Huh? High pitched squeals are what makes it all worthwhile! That's
only one step short of throwing knickers.

Have you tries varying the angle of incidence of the air blast? You
should be able to kill them.

d

--
Pearce Consulting
http://www.pearce.uk.com
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Glenn Sowell
science forum beginner


Joined: 02 Jul 2006
Posts: 9

PostPosted: Tue Jul 04, 2006 1:32 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Yeah, I tried varing the angles. Mind you, I am using a vacuum cleaner
hose which has a circular opening about 2 cm in diameter. Would a flat,
narrower opening work better? I've got that attachment too!

Glenn

In article <44aa5a87.179479656@text.usenet.plus.net>, Don Pearce
<nospam@nospam.com> wrote:

Quote:
On Tue, 04 Jul 2006 07:08:36 -0500, Glenn Sowell <sowell2@cox.net
wrote:

You are right, of course. But the notes are accompained by high-pitched
squeals. Those I don't want.

The plastic bottles do vibrate strongly, but that does not stop 2-liter
pop bottles from working nicely.

Thanks
Glenn

Huh? High pitched squeals are what makes it all worthwhile! That's
only one step short of throwing knickers.

Have you tries varying the angle of incidence of the air blast? You
should be able to kill them.

d
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Mike Amling
science forum Guru


Joined: 05 May 2005
Posts: 525

PostPosted: Tue Jul 04, 2006 1:36 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

On Tue, 04 Jul 2006 08:32:38 -0500, Glenn Sowell <sowell2@cox.net>
wrote:

Quote:
Yeah, I tried varing the angles. Mind you, I am using a vacuum cleaner
hose which has a circular opening about 2 cm in diameter. Would a flat,
narrower opening work better? I've got that attachment too!

Glenn

I think there is a very good chance you are overblowing the bottle - a
vacuum cleaner expels quite a quantity of air. Any way you could
reduce the flow rate?

d

--
Pearce Consulting
http://www.pearce.uk.com
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ari1
science forum beginner


Joined: 11 Jul 2005
Posts: 9

PostPosted: Tue Jul 04, 2006 1:55 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Don Pearce wrote:
Quote:
On Tue, 04 Jul 2006 08:32:38 -0500, Glenn Sowell <sowell2@cox.net
wrote:

Yeah, I tried varing the angles. Mind you, I am using a vacuum cleaner
hose which has a circular opening about 2 cm in diameter. Would a flat,
narrower opening work better? I've got that attachment too!

Glenn

I think there is a very good chance you are overblowing the bottle - a
vacuum cleaner expels quite a quantity of air. Any way you could
reduce the flow rate?
How about increasing pressure drop over the fan, for example by blocking

the flow into the cleaner. Or taking a vacuum cleaner with a suction
control.

The angles, opening shapes, out flow velocities etc. things that modify
the incoming boundary layer might work. The same should/could apply with
the trailing edge of the opening (effects the feedback).

It might be worthwhile to remember that from physical point of view this
is not an easy thing to evaluate/estimate/forecast.

ari

machineryacoustics.fi
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woinem1@aol.com
science forum beginner


Joined: 03 Jul 2006
Posts: 6

PostPosted: Tue Jul 04, 2006 2:23 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Glenn Sowell schrieb:


Quote:
I can excite a REALLY low note by blowing air from a vacuum cleaner

Hi Glenn,
do you have a recording of those sounds? I think it would be easier to
find the reason for those high pitches if I could put "an ear into
it"...
Uli Wahl
http://members.aol.com/woinem1/index/
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Glenn Sowell
science forum beginner


Joined: 02 Jul 2006
Posts: 9

PostPosted: Tue Jul 04, 2006 3:32 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Both Ari and Don have good suggestions, which I will try tomorrow
(Wednesday). Today is a holiday in the US and my water bottles are at
work!

Thanks
Glenn

In article <fsuqg.13989$uQ5.10877@reader1.news.jippii.net>, ari
<ari.karjalainen@NOSPAMnic.fi> wrote:

Quote:
Don Pearce wrote:
On Tue, 04 Jul 2006 08:32:38 -0500, Glenn Sowell <sowell2@cox.net
wrote:

Yeah, I tried varing the angles. Mind you, I am using a vacuum cleaner
hose which has a circular opening about 2 cm in diameter. Would a flat,
narrower opening work better? I've got that attachment too!

Glenn

I think there is a very good chance you are overblowing the bottle - a
vacuum cleaner expels quite a quantity of air. Any way you could
reduce the flow rate?
How about increasing pressure drop over the fan, for example by blocking
the flow into the cleaner. Or taking a vacuum cleaner with a suction
control.

The angles, opening shapes, out flow velocities etc. things that modify
the incoming boundary layer might work. The same should/could apply with
the trailing edge of the opening (effects the feedback).

It might be worthwhile to remember that from physical point of view this
is not an easy thing to evaluate/estimate/forecast.

ari

machineryacoustics.fi
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Greg Locock
science forum Guru Wannabe


Joined: 28 May 2005
Posts: 111

PostPosted: Wed Jul 05, 2006 12:15 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

woinem1@aol.com wrote in news:1152022998.895410.47520
@v61g2000cwv.googlegroups.com:

Quote:

Glenn Sowell schrieb:


I can excite a REALLY low note by blowing air from a vacuum cleaner


Quote:
do you have a recording of those sounds? I think it would be easier to
find the reason for those high pitches if I could put "an ear into
it"...


Let me guess, third fifth and so on harmonics.

What will you learn?

Cheers

Greg
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woinem1@aol.com
science forum beginner


Joined: 03 Jul 2006
Posts: 6

PostPosted: Wed Jul 05, 2006 3:00 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Greg Locock schrieb:

Quote:
Let me guess, third fifth and so on harmonics.

What will you learn?

I'd like to know more about the nature of those high pitches.

Are they generated at the soundhole? Then you're right with the
harmonics.
Are they generated by vibrations/ fluttering of the walls ofd the
bottle (depending where the soundhole has been placed.
Are they generated by the corrugated tube of the vacuum cleaner?
All this my ears wants to learn by the recording... Smile)
Jam and troast
Uli
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Glenn Sowell
science forum beginner


Joined: 02 Jul 2006
Posts: 9

PostPosted: Fri Jul 07, 2006 12:40 am    Post subject: Re: 5 gallon musical water bottle Reply with quote

They are generated at the sound hole.

Glenn

In article <1152111623.160600.323940@m79g2000cwm.googlegroups.com>,
<woinem1@aol.com> wrote:

Quote:
Greg Locock schrieb:

Let me guess, third fifth and so on harmonics.

What will you learn?

I'd like to know more about the nature of those high pitches.
Are they generated at the soundhole? Then you're right with the
harmonics.
Are they generated by vibrations/ fluttering of the walls ofd the
bottle (depending where the soundhole has been placed.
Are they generated by the corrugated tube of the vacuum cleaner?
All this my ears wants to learn by the recording... Smile)
Jam and troast
Uli
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Angelo Campanella
science forum Guru Wannabe


Joined: 08 May 2005
Posts: 226

PostPosted: Sat Jul 08, 2006 2:42 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Glenn Sowell wrote:
Quote:
I want to make a set of musical water bottles using the typical 5
gallon bottles found on water coolers.

That seems feasible.. filling any of them to various levels should
produce varios notes as desired.

Quote:
I can excite a REALLY low note by blowing air from a vacuum cleaner
across the top. Unfortunately, I also excite several overtones as well.

My recollection of glass 5 gallon jugs is that the empty tone is about
30 or 60 Hz. One can ecite that tone by blowing one's breath across the
open mouth of the bottle. Wine bottle (750 ml) produce about 120 Hz.

The Helmholtz frequency calculations work well for approximate
prediction of the resulting tone.

But two perturbations arise that affect tone quality:

1- The Helmholtz calculation is accurate only for sound of wavelengths
very long as compared to the length of the bottle.

2- The turbulent nature of the flow of an aistream across the opening of
the bottle produces excitation over a wide range of audio frequencies.
Sound Eigenmodes of the bottle volume of wavelengths comparable to the
dimensions of that bottle will also be excited. Prediction of the
precise eigenmode frequencies cannot be done with the Helmholtz
calculation; rather it requires the cylindrical room method, treated at
least by Morse in "Vibration and sound".

Quote:
How can I excite just the fundamental? Slower moving air? By shaping
the vacuum attachment through which is blown?

Bottle modes are excited by the turbulent velocity component along the
axis of the bottle opening centerline. The usual excitation is via the
(Von Karman) vortex street caused by the airflow over the edge of the
opening; trailing from first edge encountered by the airflow. The
frequency of that series of eddies depends on the flow velocity and
perhaps the diameter of the airstream.

Where the Helmholtz eigenmode is available, it soon becomes excited and
consequently controls the frequency of the vortex shedding rate. But it
is possible to blow with such a high velocity that higher frequency
eigenmodes that also exist for that cylindrical volume are also excited.
The mode of strongest excitation, or highest "Q" will likely dominate in
turn and control the edge vortex shedding rate for that flow condition.
I would think that the parameters that are controllable and privvy to
adjustment and selection are: Flow speed, Flow diameter, Edge sharpness
and flow incidence angle to that nearer edge.

It is all amenable to trial and error; and amenable to clever invention.

Good luck!

Angelo Campanella
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Angelo Campanella
science forum Guru Wannabe


Joined: 08 May 2005
Posts: 226

PostPosted: Sat Jul 08, 2006 2:48 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Don Pearce wrote:

Quote:
Having said all that, those plastic bottles aren't very stiff - they
vibrate strongly when you excite them that way and that absorbs much
of the sound energy. If you could get hold of stiffer bottles, like
the carboys that liquid chemicals come in, you would be able to
deliver a much more powerful sound.

Agreed.

Old experiences are with glass bottles of relatively high rigidity. The
modern plastic bottle are much less rigid, and will generally produce
lower tones. I should expect that when partly filled with water, their
tones will change and rise more rapidly. Much more trial and error is
required to achieve a useful musical scale capability...

Angelo Campanella

Quote:

d
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woinem1@aol.com
science forum beginner


Joined: 03 Jul 2006
Posts: 6

PostPosted: Sat Jul 08, 2006 7:26 pm    Post subject: Re: 5 gallon musical water bottle Reply with quote

Quote:
Old experiences are with glass bottles of relatively high rigidity. The
modern plastic bottle are much less rigid, and will generally produce
lower tones.

The problem are mainly square shaped bottles or bottles with flat
bottoms. The round bottles are no poblem in general, because its walls
don't vibrate. It is even possible to make (natural wind driven)
cylindrical organ pipes of 3-4 layers of glued paper without loss of
sound quality in comparison with metal ones.
So, one possibility to improve the sound would be to use bottles with a
cylindrical shape and to insert a rigid (or curved) bottom. A
possibility to make the sound louder would be to cout the soundhole
into the side wall of the cylindrical bottle. The length depending on
the thickness/ rigidity of the wall material. With plastic bottles,
there is in general a limit of soundhole-length. Otherwise the edges of
the soundhole begin to flutter and change the (desired?) sound...
Uli Wahl
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Angelo Campanella
science forum Guru Wannabe


Joined: 08 May 2005
Posts: 226

PostPosted: Sun Jul 09, 2006 6:24 am    Post subject: Re: 5 gallon musical water bottle Reply with quote

woinem1@aol.com wrote:
Quote:
The problem are mainly square shaped bottles or bottles with flat
bottoms. The round bottles are no poblem in general, because its walls
don't vibrate. It is even possible to make (natural wind driven)
cylindrical organ pipes of 3-4 layers of glued paper without loss of
sound quality in comparison with metal ones.

Bottles of that type will also act as a drum when struck with the
fingers or a stick... an entirely different modus operandi.

Quote:
So, one possibility to improve the sound would be to use bottles with a
cylindrical shape and to insert a rigid (or curved) bottom.

This wooud avoid the flexibele sidewall problem, but produce yet another
class of instrument, something like a wind pipe set.

Quote:
A possibility to make the sound louder would be to cout the soundhole
into the side wall of the cylindrical bottle.

The hole will change the pitch.

Quote:
The length depending on
the thickness/ rigidity of the wall material. With plastic bottles,
there is in general a limit of soundhole-length. Otherwise the edges of
the soundhole begin to flutter and change the (desired?) sound...

More invention required.

Angelo Campanella
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