کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
754698 895881 2009 8 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Can a transmission coefficient be greater than unity?
موضوعات مرتبط
مهندسی و علوم پایه سایر رشته های مهندسی مهندسی مکانیک
پیش نمایش صفحه اول مقاله
Can a transmission coefficient be greater than unity?
چکیده انگلیسی

In studying the sound transmission through panels, it is usual to consider a model based on an infinite panel. The sound transmission coefficient is defined as the ratio of transmitted power to incident power and must, therefore, be less than or equal to unity due to energy conservation. However, it is shown here that, for a finite panel, it is possible to find values of transmission coefficient that are greater than unity at certain frequencies due to the normalisation used for the incident power. This occurs at the fundamental resonance of the fluid-loaded panel. Example results are presented for a simple circular piston and then for a flexible rectangular panel and an explanation for this phenomenon is provided. In effect, the panel is excited by a sound field that is much larger than its own surface and attracts sound power from a wide region of the incident field. This result stands as an interesting test case for calculation methods where the occurrence of transmission coefficients greater than unity should not necessarily be seen as an error in the calculation.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Acoustics - Volume 70, Issue 5, May 2009, Pages 681–688
نویسندگان
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