![]() The experimental average value of \\exp ) is an improved value by the use of the concept of the central limit theorem. In this study, the speed of sound v in the air is determined using the identification of maxima of interference from two synchronous waves at frequency f. Audible sound frequencies for human ears range from 20 to 20 000 Hz. In fluids like air, sound waves propagate through successive longitudinal perturbations of compression and decompression. Sound is an example of a mechanical wave. Mechanical waves propagate through material media. ![]() The theoretical model of the proposed metamaterial open panels is derived using an effective medium approach and verified by numerical and experimental investigations.ĭetermining the speed of sound in the air by sound wave interference As a result, low- frequency broadened sound transmission reduction is realized efficiently in the present metamaterial panels. Owing to the dispersive characteristics of the present metamaterial panels, local resonances that trap sound in the partitions also occur at higher frequencies, exhibiting negative effective bulk moduli and zero effective velocities. Global resonances originating from slow waves realized by multiply inserted, elaborately designed subwavelength rigid partitions between two thin holey plates contribute to sound transmission reductions at lower frequencies. Here, we propose slow- wave metamaterial open panels that can dramatically lower the working frequencies of sound transmission loss. When open holes must be inserted in panels for heat transfer, ventilation, or other purposes, the efficient reduction of sound transmission through holey panels becomes difficult, especially in the low- frequency ranges. Sound transmission reduction is typically governed by the mass law, requiring thicker panels to handle lower frequencies. ![]() Yang, Jieun Lee, Joong Seok Lee, Hyeong Rae Kang, Yeon June Kim, Yoon Young Slow- wave metamaterial open panels for efficient reduction of low- frequency sound transmission
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |