[Harp-L] Re: Waxing Rivets for Overbends [plus!]

[Bobbie Giordano <bobg@xxxxxxx>]

Jonathan Metts answered Michelle's comments, saying:
>>Bobbie, it seems like finite element analysis would be a natural for 
>>stuying the dynamics of a vibrating free reed.  Do you happen to know
>>hether anyone has used FIA to characterize the complex motion(s) of a 
>>free reed as it vibrates under different input conditions?  That would 
>>make a nice thesis project for a harmonica-playing engineering student, 
>>don't you think?
>
>Finite element analysis would show you what the reed is doing and how it 
>is vibrating, but you would have to model the forces on the reed to get 
>results, and that could be very difficult without understanding more about 
>the airflow.

Firstly, thanks, Michelle for the response!  I know the possibility of this
sort of analysis has come up in past years on Harp-L, at times from Vern
Smith, I believe, who probably also knows a lot about this topic.  However,
from my very limited knowledge of these academic areas, I agree with
Jonathan, in that FEA would perhaps be better for evaluating the differing
properties of materials used as harmonica reeds; ie, how well they hold up
physically and pitch-wise in such an application.  But, there is cross-over,
too, since reed construction and design very likely influences the air flow
effects involved in the reed's motion-induced "noises".

>I would suggest a computational fluid dynamics approach (CFD) first.
>It would show the nature of the airflow around the reed and through
>the slot as a function of time.  CFD can show you the vortices, 
>turbulence, etc. and it can help you determine the force on the 
>surrounding structures at various points and time markers.

Exactly what I was trying to address in my post.  As your response came in,
Jonathan, I was preparing another email on this subject, so I'll just defer
to what I was already writing and say thanks to both of you for your remarks,
and to Jonathan for bolstering my approach to the issue I was addressing.
Thanks, too, if you do manage to interest some student in taking on this
interesting project.

Wish I could afford to go back to college............  sigh.

Cheers!
Bobbie