ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
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what you are after is called a "Schlieren optical system
google that term to find a bit more about it
(edmond sci used to distribute 4 and 6 inch versions, they may still).
check out
http://www.mne.psu.edu/psgdl/facilities_Optical.htm
at the Pen State to see what is possible, and these guys may also be happy to offer some help/advice.
A Schlieren system visualises density differences in the air. So you may find that you need to run your organ pipe on cool, or warm air to maximise the visual impact.
they can take a bit of fiddling to get alinged, and can take up a bit of space ( as they need long optical paths for maximum sensitivity) but they are quiet reliable once set up, and bolted down.
good luck.
Stuart Kohlhagen
leader new concepts
Questacon- The national science and technology centre
Canberra
-----Original Message-----
From: Informal Science Education Network on behalf of Joe Ruggiero
Sent: Mon 1/16/2006 8:38 AM
To: [log in to unmask]
Subject: Re: Seeing airflow
ISEN-ASTC-L is a service of the Association of Science-Technology Centers
Incorporated, a worldwide network of science museums and related institutions.
*****************************************************************************
Hi Cobie,
I have a habit of exposing my ignorance but I think you can achieve some
of what your after with a simple set up. Just to try, place a small
mirror (square foot mirror tile would work okay) outside and aim it so
it shines a little piece of sunlight into a somewhat dark room (sunlight
is so bright that the room doesn't really have to be very dark.) In the
beam of sunlight place a lit match or other heat source. In the shadow
on the wall you should very clearly see convection currents swirling off
the match.
I know the match trick works fine - it gives off enough heat to overcome
other convection currents in this very uncontrolled set up. In a more
controlled environment even the heat off your hand can work. I'm not
sure about the organ pipe, but in a more tightly controlled set up is
should work fine as well.
I think the sunlight basically takes care of most of your optics. That
light all ready arrives collimated, more or less. The set up you
describe sounds like it provides a much more controlled, lab-like,
environment, which frees you from sunlight and makes the whole thing
portable. I sure do like the simplicity of the sun, though.
Try the little demo with the sunlight and then look up Schlieren Optics
on the web.
I hope this helps. If you discover that I've got it all wrong, please
let me know.
All the best to you folks over there.
Joe R
www.TheExhibitGuys.com
Cobie Howard wrote:
>ISEN-ASTC-L is a service of the Association of Science-Technology Centers
>Incorporated, a worldwide network of science museums and related institutions.
>*****************************************************************************
>
>Hi,
>We are trying to build an exhibit that allows visitors to see a shadow of
>the airstream that flickers in and out of the mouth of an organ pipe. I
>have heard that this is possible using some arrangement of a strobe light,
>polarizing filters and collimating lenses. Does anybody have any tips or
>resources to help us do that?
>Thanks,
>Cobie Howard
>Exhibit Developer
>Explora Science Center and Children's Museum of Albuquerque
>505-224-8306
>
>
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More information about the Informal Science Education Network and the
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To remove your e-mail address from the ISEN-ASTC-L list, send the
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To remove your e-mail address from the ISEN-ASTC-L list, send the
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