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

• Published in: The Journal of the Acoustical Society of America Vol. 125; no. 2; p. 664
• Main Authors: Bin, Jonghoon, Yousuff Hussaini, M, Lee, Soogab
• Format: Journal Article
• Language: English
• Published: United States 01.02.2009
• Subjects: Acoustics; Algorithms; Computer Simulation; Linear Models; Models, Theoretical; Motion; Numerical Analysis, Computer-Assisted; Pressure; Reproducibility of Results; Sound; Surface Properties; Time Factors
• ISSN: 1520-8524
• DOI: 10.1121/1.2999339

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 surface and the other is acoustic wave propagation in a duct with a finite impedance wall. Both single-frequency and broadband-frequency simulations are performed within the framework of linearized Euler equations. A high-order dispersion-relation-preserving finite-difference method and a low-dissipation, low-dispersion Runge-Kutta method are used for spatial discretization and time integration, respectively. The results show excellent agreement with the analytical/experimental results at various frequencies. The method accurately predicts both the amplitude and the phase of acoustic pressure and ensures the well-posedness of the broadband time-domain impedance boundary condition.