Micro-perforated sound absorbers with sub-millimeter size holes can provide high absorption coefficients. Various types of micro-perforated absorbers are now available in literature for different applications. This thesis presents results of work
on the development of an effective single layer micro-perforated sound absorber from the commercial composite material Parabeam with micro diameter holes drilled on one side. Parabeam is used as a structural material made from a fabric woven out of a E-glass yarn and consists of two decklayers bonded together by vertical piles in a sandwich structure with piles (thick fibers) woven into the decklayers. The thesis includes, the analytical model developed for prediction of absorption coefficients, finite element solution using commercial software MSC.ACTRAN and experimental results obtained from impedance tube measurements. Different absorption characteristics can be achieved by variations in hole diameter and hole spacing. Based on the developed models, an optimization is performed to obtain an efficient absorber configuration. It has been anticipated that
several different and interesting applications can be deduced by combining structural and sound absorption properties of this new micro-perforated absorber along with conventional fibrous absorbers.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/3/12610064/index.pdf |
| Date | 01 October 2008 |
| Creators | Onen, Onursal |
| Contributors | Caliskan, Mehmet |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | M.S. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
Page generated in 0.003 seconds