Water as a sound deadening medium in enclosures???

[HK26147]

Sasi: I did misunderstand your reference.
Apparently sound attenuation of snow has been studied extensively including:
http://www.env-acoust.k.u-tokyo.ac.jp/public/b/b008.pdf

Regards
Syd

 

[Pano]

......buried it in 300lb of sand in a trash bucket...

Sand good = yes. Heavy tho.....

Originally posted by George
I think that this is as advanced as it gets

Now that's a cool device - thanks for posting! Did you take a look at the app notes? Some extremely cool stuff there. The 3D look at wavefronts is wonderfull. There was some stuff done like that in a more primitive way back in the 30s and 50s. Have always wanted to do the same. This thing is seriously cool. 😎

 

[Alex from Oz]

Here's some interesting stuff - QuietWave visco-elastic membrane from Oz.

 

[gpapag]

Ref. Panomaniac post#62

Now that's a cool device - thanks for posting! Did you take a look at the app notes? Some extremely cool stuff there. The 3D look at wavefronts is wonderfull. There was some stuff done like that in a more primitive way back in the 30s and 50s. Have always wanted to do the same. This thing is seriously cool

I was searching for various sensors for predictive maintenance purpose actually, so I was linked to some pdfs that were addressing the p-u approach.

For our purpose, the reasoning for using a miniature air particles velocity sensor to listen to the sound produced by a vibrating surface can be summarized in the following:

In the free field the sound pressure level and particle velocity level are of similar magnitude.

If a sound wave (background noise) reflects on a rigid surface, the sound pressure doubles and the particle velocity reduces to zero close to this rigid surface.

Close to a vibrating structure (sound emitting surface) a high particle velocity level and a low sound pressure level is observed.


Detailed pdf

http://www.microflown.com/data/2009_SAE_EOL.pdf

http://www.microflown.com/data/2005_Finn_Novem_calibration.pdf

Regards
George

 

[Pano]

Wow! Cool stuff. Much reading and thinking to do...

Thanks for posting that. =)