Sound absorption by porous materials I
نویسندگان
چکیده
منابع مشابه
Sound Absorption of Porous Material in Combination with Perforated Facings
The absorption characteristics of porous absorbers in combination with perforated facings was investigated. The effect of the hole size, hole pattern and open area ratio were examined. The absorption coefficients for an absorber of uniform cross-section were compared to those for an absorber with a tapered cross-section for various volumes of absorbent and different perforated facings.
متن کاملExtraordinary absorption of sound in porous lamella-crystals
We present the design of a structured material supporting complete absorption of sound with a broadband response and functional for any direction of incident radiation. The structure which is fabricated out of porous lamellas is arranged into a low-density crystal and backed by a reflecting support. Experimental measurements show that strong all-angle sound absorption with almost zero reflectan...
متن کاملHydrogen Absorption Property of Pd-Doped Porous Materials
In electrochemical loading of Pd with deuterium, it has been known that attaining a D/Pd value larger than 0.88 is necessary for triggering excess heat effects [1]. It has been reported by Arata and Zhang that the heat arising from D-D nuclear fusion reaction in solid is observed simply by pressurizing nano-Pd/ZrO2 system with deuterium gas [2]. It seems that nano-scale Pd particles absorb more...
متن کاملSound propagation in and low frequency noise absorption by helium-filled porous material.
Low-frequency noise is difficult to deal with by traditional porous material due to its inherent high acoustic impedance. This study seeks to extend the effective range of sound absorption to lower frequencies by filling a low density gas, such as helium, in the porous material. Compared with conventional air-filled absorption material, the helium-filled porous material has a much reduced chara...
متن کاملSound absorption of porous substrates covered by foliage: experimental results and numerical predictions.
The influence of loose plant leaves on the acoustic absorption of a porous substrate is experimentally and numerically studied. Such systems are typical in vegetative walls, where the substrate has strong acoustical absorbing properties. Both experiments in an impedance tube and theoretical predictions show that when a leaf is placed in front of such a porous substrate, its absorption character...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Applied Scientific Research, Section B
سال: 1950
ISSN: 0365-7140
DOI: 10.1007/bf02919928