The study on sound-absorbing properties of oblique micro-perforated panel

• Main Authors: Chung-chiech Chiang, 江仲傑
• Other Authors: Rong-Ping,Lai
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/86120903533513437360

碩士 === 國立成功大學 === 建築學系專班 === 96 === According to Dr. Maa’s theory, the sound absorption coefficient of ordinary micro-perforated panel (address as MP)absorber can be predicted with diameter of opening, percentage of perforated area, back air space depth. The oblique micro-perforated panel (address as OMP) is distinct to MP in terms of structure, such as oblique appearance, and open holes are not orthogonal to the panel’s surface. The study explored the differences of sound absorption’s character between MP and OMP, and the effect of structure factors on the sound absorption coefficient of OMP. The conclusion of the study including： 1.OMP structures could be absorbers with good sound absorption’s characters ( the averaging sound absorption coefficients reach 0.5 ) . 2.The averaging sound absorption coefficient of MP structure possessing the same hole area（take small-hole side area for OMP）, percentage of perforated area, depth of back opening and air space as OMP structures , is greater than MP structures taking large-hole side area and hole area situated at the center of depth for OMP, and the difference between that and OMP structure is little than differences as MP structures taking the other two hole areas. 3.The sound absorption coefficients of OMP structure at 3150Hz and 4000Hz are greater than that of MP structures possessing the same structures. 4.In the range of sample structures the research adopted, reducing percentage of perforated area, or increasing any of hole depth, hole section slope, small-hole side area, back air space depth, will observably raise the averaging sound absorption coefficients of OMP. Reducing large-hole side area or hole appearance-index, small-hole side surface uneven grade, will raise the averaging sound absorption coefficients too, but the inference is not notable. 5.Using sound absorption coefficients of MP as norm of comparison could make the inference of changing small-hole side area or small-hole side appearance-index obvious.