Numerical Analysis of Three-Dimensional Sound Field in a Duct with Eccentric Slit-Like Expansion.

Abstract

A numerical analysis is developed to the three-dimensional sound field in cylindrical duct with eccentric slit. A linearized unsteady Euler equation for acoustic disturbance is solved by a fourth-order accurate finite difference method. The boundary conditions at the curved rigid surface, such as the duct wall, are implemented properly for the linearized Euler equations. The three-dimensional structures of the sound fields are obtained for the several eccentricities of slit. The computed result shows that each eccentric slit has two different resonant frequencies, which are fully consistent with our previous experimental data.