Equivalent noise source strength for a ship
Equivalent noise source strength for a ship
(OP)
A shipyard has asked us for measure underwater radiad noise from the hull of a vessel, and they are also asking us to convert the pressure levels obtained to an equivalent noise source strength. Does anyone knows how to calculate the noise source strength of a vessel from the radiated noise referenced at 1 meter? Wich is right model dipole or monopole...?
Thanks for your anwers.
Thanks for your anwers.





RE: Equivalent noise source strength for a ship
I suspect you need to turn your far field sound pressure measurements into intensity estimates, multiply by the area of each patch, to give a power flux normal to the surface, and then turn that into a power spectrum. I have forgotten the grisly details, any undergraduate acoustics text will have the equations.
Your industry may have a standard approach, the automotive industry certainly does, look for SAE standards on sound power measurement, in particular the hemisphere technique. There is a very similar DIN procedure for estimating the sound power from appliances.
Note that you will have to make some interesting decisions about coherence.
Cheers
Greg Locock
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