Lighthill's eighth power law
In aeroacoustics, Lighthill's eighth power law states that power of the sound created by a turbulent motion, far from the turbulence, is proportional to eighth power of the characteristic turbulent velocity, derived by Sir James Lighthill in 1952. This is used to calculate the total acoustic power of the jet noise. The law reads as
where
The eighth power is experimentally verified and found to be accurate for low speed flows, i.e., Mach number is small,. And also, the source has to be compact to apply this law.
