Estimation of Total Acoustic Power for a Still Acoustic Source

How can I quickly estimate the total acoustic power of my still acoustic source?

Such scaling law only provides a first trend that remains useful to identify key factors that drive aerodynamic noise generation.

Important limitations remain:

  • Valid for low-Mach number flow
  • Valid only for compact acoustic sources
  • Only takes into account the monopole contribution
  • Assumes the source is not moving in the flow (i.e. still source)

If source is not compact, the source distribution can create interferences between different portions of the acoustic source, which can lead to a overall reduced acoustic efficiency.

Remember that in Ansys Fluent, you can also use the Proudman’s formula to assess the acoustic power generated by isotropic turbulence without mean flow. Assumptions are quite close to that of the previous law but the formulation relies on the RANS turbulent content of any region inside the computational domain, not necessarily close to the main acoustic source!

Please see attached document for further details.