"The information that a Rijke tube has oscillated with a component
at the first overtone (in this case the octave) comes as a great
surprise to me because that would place the gauze at a *node* of the
oscillation, certainly a clue I did not have before. If it is true it
is very surprising."
To which you responded:
"Perhaps this is a pressure node rather than a displacement node."
The gauze is placed one fourth the way up the tube. The first overtone
for an open tube is the second harmonic. This harmonic has antinodes at
at the center and has displacement nodes between each antinode. It seems
to me that this places the gauze at a displacement node and pressure
antinode of the first overtone. (Displacement nodes coincide with
pressure antinodes and vice versa.)
Gene
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Eugene (Gene) P. Mosca Phone 410-293-6659 (Fax 3729)
Physics Department 410-267-0144 Home
572 Holloway Road 610-683-3597 Summer
U.S.Naval Academy Mailstop 9C, Michelson Rm 339
Annapolis MD 21402 email: mosca@nadn.navy.mil
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