افزایش پهنای باند بسامدی جاذب‌های صوتی چندلایه تخت متشکل از ماده متخلخل، صفحه سوراخ‌دار و فاصلۀ هوایی

نوع مقاله : مقاله پژوهشی

نویسندگان

1 مهندسی صدا، دانشکده فنی و مهندسی، دانشگاه صدا و سیما، تهران، ایران

2 مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه صداوسیما، تهران، ایران

3 فیزیک، دانشکده فنی و مهندسی، دانشگاه صداوسیما، تهران، ایران

چکیده

چکیده: امروزه جاذب‌هایی که نوفه را در پهنای وسیعی از بسامدها جذب کنند و نیز کمترین فضا را در سازه به‌خود اختصاص دهند، بسیار مورد توجه است. در این مقاله با استفاده از ترکیب مادۀ متخلخل، صفحۀ سوراخ‌دار و فاصلۀ هوایی، چهار نمونه اولیه پیشنهاد شده و در ادامه به منظور افزایش میزان و پهنای باند جذب صوتی، مشخصه‌های نمونه‌ای که بیشترین جذب صوتی را داشته، استخراج شده است. برای بررسی عملکرد جذب صوتی ساختارهای ارائه شده از روش ماتریس تبدیل و روش اجزا محدود استفاده شده است. برای صحه‌گذاری مدل ریاضی و نتایج روش اجزا محدود، نتایج نظری و تجربی برای دو نمونۀ مختلف از جاذب مرکب مقایسه شده‌اند که تطابق مناسبی را نشان م یدهند. نتایج نشان می‌دهند که میانگین ضریب جذب صوتی مدل بهبود یافته، با ضخامت نهایی 51 میلیمتر در گسترۀ بسامدی 9/ 0، Hz – 6000 Hz 1 است که نسبت به ساختارهای ارائه شده در کارهای گذشته، بدون افزایش ضخامت کلی، % 5 بهبود در میزان جذب دارد. به عبارتی، با ضخامت کمتری به همان ضریب جذب متداول در ساختارهای موجود در صنعت می توان دست یافت و این امر از نظر مهندسی بسیار مهم است؛ چون فضای کمتری اشغال می شود و هزینه اجرا نیز کاهش می یابد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Increasing the Frequency Band of Sound Absorption for Flat Multi-Layered Absorbers Consisting of Porous Material, Perforated Panel and Air-Gap

نویسندگان [English]

  • M. Broghany 1
  • S. Saffar 2
  • S. Basirjafari 3
1 Department of Acoustics and Audio Engineering, IRIB University, Tehran, Iran
2 Department of Acoustics and Audio Engineering, IRIB University, Tehran, Iran
3 Department of Acoustics and Audio Engineering, IRIB University, Tehran, Iran
چکیده [English]

Sound pollution, especially in metropolises, is a critical issue at the time being. Hence, appropriate sound absorbers which absorb higher noise in a wide range of frequencies are desirable especially when less occupied space is needed. In the present study, four primary models are proposed by combination of the porous material, micro-perforated panels and air gap. Afterwards, sound absorption coefficient was maximized in every proposed model by employing both analytical approach (transfer matrix method) and finite element method (by COMSOL Multi-physics version 4.4). Verification has been carried out by comparison with the theoretical and experimental results of previous studies. The results showed well agreement between present and previous results. Consequently, an optimized model by maximum sound absorption coefficient was proposed. The proposed model showed the average of sound absorption coefficient equal to 0.9 which is approximately 5% more than previous studies in the frequency range of 1 to 6000 Hz for 51 mm thickness of panel. In other words, the presented structure, with a less thickness has the same sound absorption coefficient of the commercial industrial structures. This is very important in terms of engineering because the presented sound absorber takes up less space and also, running costs are reduced.

کلیدواژه‌ها [English]

  • Sound absorption coefficient
  • Composite absorber
  • Transfer matrix method
  • finite element method
  • Perforated panel
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