Time-domain Impedance Boundary Conditions for Computational Acoustics and Aeroacoustics

Groups Generated by Wave-duct Acoustics with Impedance Boundary Conditions

Source-free wave-duct acoustics formulated as an initial value problem for the wave equation with impedance boundary conditions is considered. Properties of the corresponding C0-groups and their generators are given by emphasizing the spectral representation of these operators. Research supported in part (H.T.B.) by the Air Force O ce of Scienti c Research under grant AFOSR-90-0091. This resear...

A residual-potential boundary for time-dependent, infinite-domain problems in computational acoustics.

A theoretically exact computational boundary is introduced, that is based on modal residual potentials for the spherical geometry. The boundary produces a set of first-order, uncoupled ordinary differential equations for nodal boundary responses, and a set of uncoupled time-stepping equations for modal boundary responses. The two sets are coupled through nodal-modal transformation based on the ...

Time Domain Boundary Element Method for Room Acoustics

Broadband impedance boundary conditions for the simulation of sound propagation in the time domain.

An accurate and practical surface impedance boundary condition in the time domain has been developed for application to broadband-frequency simulation in aeroacoustic problems. To show the capability of this method, two kinds of numerical simulations are performed and compared with the analytical/experimental results: one is acoustic wave reflection by a monopole source over an impedance surfac...

The Use of Surface Impedance Boundary Conditions in Time Domain Problems: Numerical and Experimental Validation

This paper analyzes the limits of applicability of the time domain surface impedance concept. Numerical results obtained by the boundary element formulation employing time domain surface impedance boundary conditions (SIBCs) of different orders of approximation are compared with experimental data and numerical results obtained using the finite element method. An analytical formula for evaluatio...