Acoustic Filters: Part I - Design and Analysis
Hubert Bukac · Purdue e-Pubs (Purdue University System) · 2006
The application of the solution of the wave equation to model frequency characteristics of acoustical filters is reviewed.It was first applied by Davies et al. (1954).A version of this method, which is suitable for application on computers, was developed by Eversman (1987).It equates pressure and volume velocity at each boundary at which the acoustic duct changes its cross-section, or acoustic impedance.In this sense, the method can be considered as one-dimensional boundary element method.Its advantage over the four-pole parameter method is in that that it enables detailed view of the inside of the system.Standing waves of pressure and volume velocity can be calculated at any arbitrarily chosen location in the system for any frequency.Velocity of sound, density of gas and velocity of flow can be different in every part of the system.Furthermore, modeling and analysis of multiple parallel acoustic paths does not impose any difficulty.