SOLUTION OF COUPLED ACOUSTIC PROBLEMS: A PARTIALLY OPENED CAVITY COUPLED WITH A MEMBRANE AND A SEMI-INFINITE EXTERIOR FIELD
✍ Scribed by Y.-H. KIM; S.-M. KIM
- Publisher
- Elsevier Science
- Year
- 2002
- Tongue
- English
- Weight
- 297 KB
- Volume
- 254
- Category
- Article
- ISSN
- 0022-460X
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✦ Synopsis
There have been many attempts to understand the coupling phenomena between a solid structure and the surrounding #uid. However, the studies were restricted to interaction only between a structure and a "nite cavity or a structure and acoustic "eld of in"nite size. The system that we have studied has a structure that faces both a cavity of "nite size and an external "eld of semi-in"nite size. We also allow a hole, which can directly interact with the cavity as well as the external "eld. This con"guration, therefore, provides two di!erent interactions, or communication means. One is the "nite structure and the other is the hole of "nite size. This paper studies as to how these two components interact with the other two systems: the "nite cavity covered by the structure and the hole, and the semi-in"nite #uid. For simplicity, a two-dimensional and partially opened cavity coupled with a membrane and an exterior "eld was selected. The solution has to be found by solving a boundary value problem, but this case has to do with the boundaries that have two di!erent conditions: one is the membrane and the other is the hole. The solution has been found in terms of the modal functions that satisfy the boundary conditions of "nite cavity, membrane and hole. Non-dimensional coupling coe$cients are obtained from the solution. The results exhibit that the coupling e!ect gives additional peaks and troughs in the averaged pressure of the cavity. These peaks and troughs are symmetrically arranged with respect to Helmholtz frequency of the cavity. The strong coupling occurs at the trough frequencies where the membrane interacts actively with the cavity and the exterior "eld.