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Hydrophone - turbulence measurements

Started by e.ta...@uq.edu.au June 9, 2010
Hi all,

I have some wave (.wav) files from measurements using a hydrophone in an agitated tank. From a FFT I can see peaks at the impeller frequency (1000rpm ~ 17 Hz) and its harmonics.
However, I would like to separate the "audio pressure fluctuation" from the "fluid turbulent pressure fluctuation". Is it possible? Is there any kind of filter I should use?

Extra information: I am processing it using LabView. My original signal are recorded in a voice recorder from an amplifier (1V/Pa), then it is converted to "lvm" file and processed in LabView - using FFT. The FFT'd signal is displayed and the impeller rotating frequence and its harmonics can be seen.
More, because I'm using a voice recorder, the frequency range is very low (0-500 Hz).

Many thanks in advance!

Kind Regards.
Can you describe the spectral or temporal characteristics of the "audio pressure fluctuation" and "fluid turbulent pressure fluctuation"?

Hugh

--- On Wed, 6/9/10, e...@uq.edu.au wrote:

From: e...@uq.edu.au
Subject: [audiodsp] Hydrophone - turbulence measurements
To: a...
Date: Wednesday, June 9, 2010, 12:20 AM

 

Hi all,

I have some wave (.wav) files from measurements using a hydrophone in an agitated tank. From a FFT I can see peaks at the impeller frequency (1000rpm ~ 17 Hz) and its harmonics.

However, I would like to separate the "audio pressure fluctuation" from the "fluid turbulent pressure fluctuation". Is it possible? Is there any kind of filter I should use?

Extra information: I am processing it using LabView. My original signal are recorded in a voice recorder from an amplifier (1V/Pa), then it is converted to "lvm" file and processed in LabView - using FFT. The FFT'd signal is displayed and the impeller rotating frequence and its harmonics can be seen.

More, because I'm using a voice recorder, the frequency range is very low (0-500 Hz).

Many thanks in advance!

Kind Regards.