Abstract    In this paper, an analytical method was developed based on Statistical Energy Analysis framework to evaluate sound transmission loss through ventilated windows. Results of the mathematical model were validated against reported experimental data for a ventilated window and a good agreement was shown. To evaluate the efficiency of the ventilated window in provision of desirable indoor acoustic comfort, first, the outdoor noise spectra were classified into three categories of car, railway and airplane noises. Then, the indoor noise spectra resulted by the outdoor noise spectra and sound transmission loss of the ventilated window were transformed to single-rating noise criteria and were compared to the indoor noise level limits recommended by the acoustic standards. The results showed the acceptance of the indoor noise level made by the ventilated window. To recognize how the effective factors improve the acoustic performance of the ventilated window, the effect of window aspect ratio, channel thickness and opening size on Sound Transmission Class (STC) were studied. The results revealed that the ventilated window with higher aspect ratio and wider airflow channel has the higher STC while widening the opening size reduces the sound insulation.

Keywords    Ventilated window, Statistical Energy Analysis, Sound insulation, Traffic noise spectra, Sound transmission loss, Acoustic comfort

چکیده    در مقاله حاضر یک روش تحلیلی بر مبنای رویکرد تحلیل آماری انرژی برای ارزیابی عملکرد صوتی پنجره تهویه­­ شونده توسعه داده شده است. نتایج این مدل ریاضی با داده­ های آزمایشگاهی موجود در مقالات اعتبارسنجی شد و تطابق خوبی بین این نتایج مشاهده شد. برای ارزیابی کارایی پنجره تهویه­ شونده در تأمین آسایش آکوستیکی فضای داخل ابتدا طیف نوفه ­های ترافیکی محیط خارج در سه دسته نوفه­ خودرو، راه­آهن و هواپیما طبقه ­بندی شد. سپس طیف نوفه محیط داخل حاصل از این نوفه­­ ها و میزان تلفات صوتی پنجره محاسبه شد و با مقادیر نوفه مجاز پیشنهادی توسط استانداردهای صوتی مقایسه گردید. نتایج این مقایسه حاکی از مقبولیت تراز صوتی محیط داخل ناشی از پنجره تهویه­­ شونده است. همچنین برای تشخیص نحوه تأثیرگذاری فاکتورهای مؤثر بر عملکرد صوتی پنجره تهویه­ شونده، اثرتغییرات سه فاکتور نسبت ­منظر ، ضخامت کانال و اندازه دهانه ­های ورودی و خروجی پنجره بر شاخص کلاس انتقال صوت مطالعه شد. نتایج نشان داد که پنجره تهویه ­شونده با نسبت منظری و ضخامت کانال بیشتر مقادیر کلاس انتقال صوت بالاتری به همراه دارد در حالی­که افزایش اندازه دهانه ورودی و خروجی منجر به کاهش کلاس انتقال صوت و تضعیف عملکرد صوتی پنجره می ­شود.

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