As a rule of thumb, the perceived noise from a source falls by 6 dBA with every doubling of the distance from the source. If a 1 MW wind turbine (FIGURE) produces 103 dBA of noise within one metre of its base, estimate the distance from the turbine at which the noise can be reckoned to have fallen below the background noise level of 40 dBA.
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Noise intensity is measured in terms of noise level, which is given as:
b = 10*log(I/Io)
Where b is noise level in dB (here A corrsponds to frequency range).
I : intensity at a given point = Source Power (P)/Surface area (A)
Surface area = area of a virtual surface which has same noise level. Generally the sphere is considered a sphere, with area 4*pi*r^2. where r is the distance from the ...
In this problem, we estimate distance where noise due to a wind turbine vanishes. Basic concept is to find the distance where turbine noise level becomes smaller than background noise.