Abstract
The impedance condition in computational aeroacoustic applications is required in order to model acoustically treated walls. The application of this condition in time-domain methods, however, is extremely difficult because of the convolutions involved. In this paper, a time-domain method is developed which overcomes the computational difficulties associated with these convolutions. This method builds on the z-transform from control and signal processing theory and the z-domain model of the impedance. The idea of using the z-domain operations originates from the computational electromagnetics community. When the impedance is expressed in the z-domain with a rational function, the inverse z-transform of the impedance condition results in only infinite impulse response type, digital, recursive filter operations. These operations, unlike convolutions, require only limited past-time knowledge of the acoustic pressures and velocities on the surface. Examples of one-and two-dimensional problems with and without flow indicate that the method promises success in aeroacoustic applications.
Original language | English (US) |
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Pages (from-to) | 277-296 |
Number of pages | 20 |
Journal | Journal of Computational Acoustics |
Volume | 5 |
Issue number | 3 |
DOIs | |
State | Published - Sep 1997 |
All Science Journal Classification (ASJC) codes
- Acoustics and Ultrasonics
- Applied Mathematics