Numerical and Experimental Study of Acoustic Damping Generated by Perforated Screens.

Abstract

A model is presented to compute the acoustic impedance of perforated screens with bias flow. Different incompressible submodels are combined to simulate the bias flow regimes ranging from the nonlinear one (no bias flow) to the linear one (bias flow velocity larger than acoustic velocity). Experimental fits are employed to express the orifice end correction as a function of both acoustic and bias flow velocity. The validation of the model is performed for low bias flow Mach numbers and low orifice radius Helmholtz numbers by varying perforated screen geometry, bias flow velocity, and acoustic pressure amplitude.