| Zugriffsnummer | 24913 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Investigations on numerical stability of 1-d linear acoustic models of perforated pipe elements |
| Autor(in); Institution |
Bachner, Bernhard Karl; 1.7, Akustik und Dynamik, PTB-Braunschweig
|
| Quelle/Jahr | Recent developments in acoustics, noise and vibration : the 17th International Congress on Sound and Vibration, ICSV17 ; proceedings:(2010), 8 S. |
| Availability | [CD-ROM] ; file name: papers\\665.pdf |
| Herausgeber(in) |
Elnady, Tamer
|
| Verlag | Cairo: IIAV |
| Konferenzangaben | International Congress on Sound and Vibration - ICSV17, Cairo, 18-22, July, 2010, Egypt |
| Freie Schlagworte | Duct acoustics ; perforated pipe muffler ; linear model ; numerics |
| Zusammenfassung | A commonly used element for silencer systems is the perforated two- or multiple-duct. The importance of this kind of acoustic wave guides is indicated by the number of publications on modelling the wave propagation within such a component. Restricting to the linear and 1-dimensional case with harmonic motion, a continuous modelling approach leads to a system of coupled first-order ordinary differential equations of the state variables as functions of the duct coordinate. Besides analytical solutions for special cases, the general case including so called inhomogeneous perforated ducts can be solved only numerically. An important aspect of a numerical solution is the stability of the underlying algorithm. In contrast to the comprehensive literature on modelling perforated ducts, publications focusing the issue of numerics are rather rarely found. For the first time Kar and Munjal addressed this problem in their publication on a boundary-condition-transfer algorithm. The presented paper resumes the source of numerical instabilities. From detailed knowledge of the root cause of the numerical problems a simpler way of- applying the boundary conditions to the transfer matrix is derived. In some cases, the boundary conditions on the duct ends are not know a priori (e.g. a so-called three-pass muffler). It is verified that the application of an already published alternative formulation for duct networks intrinsically yields stable results. The capability of the newly developed procedures is demonstrated by means of examples for a conical concentric tube resonator and a three-pass-muffler. |
