Hydro-acoustic numerical methodology to compute noise generated by perforated plates in duct systems

The paper presents an innovative numerical methodology to determine hydro-acoustic behavior of perforated plates. One of the main objectives is to have a methodology that ensures a good prediction of radiated noise in ducts with a limited computational cost. The initial assessment is carried out considering the entire perforated plate. The acoustic source is determined by applying Lightill Analogy to the CFD results from LES for the whole perforated plate. An acoustic simulation is then performed to determine the dynamic pressure in the duct on either side of the perforated plate. An experimental set-up is built in order to obtain the noise generated by the perforated plate. It also allows to assess the validity of the established method. A good correlation is observed in terms of dynamic pressure upstream and downstream the perforated plate. An optimization of the method is then carried out to reduce the computational time by determining the acoustic source generated by a unit hole. This source is then applied in the acoustic simulation to each hole of the perforated plate. Comparison with measurements is also satisfactory for this simplified method.