The Multi-Microphone-Method (MMM) is used to reconstruct the acoustic field in a given geometry. If we know the mean flow, the MMM can be useful when we want to estimate the acoustic velocity from pressure measurements. In fact, if we have at least 2 measurements of pressure and/or velocity we can obtain a third one at a different location using this method.
MMM Tutorial
In the following part of the tutorial, we reconstruct the acoustic velocity using pressure measurements and then we compare it to the velocity measured by a hot wire anemometer. You can see the result in the following animation.
- On the top left we record the velocity measured by the hot wire at a location x = 0.2 m (red).
- On the middle left we show two pressure measurements at x = -0.2 m (dark blue) and x = -0.4 m (blue).
- On the top right we plot in red the signal from the hot wire (same as in the top left) and in blue the signal reconstructed from the pressure measurements. They are almost on top of each other!
- At the bottom we show the acoustic pressure field and the location of the probes.
Once you have downloaded the files from the links at the top of the page, open the following one:
- Day 1 - Day 4 \ WK01-MMM.mlx