Acoustic properties of sintered FeCrAlY foams with open cells (Ⅱ): Sound attenuation  

作　　者：M. KEPETS A. P. DOWLING2 

机构地区：[1]Cambridge University Engineering Department, Cambirdge CB2 1PZ, U.K.

出　　处：《Science China(Technological Sciences)》2008年第11期1812-1837,共26页中国科学（技术科学英文版）

基　　金：the National Basic Research Program of China (Grant Nos. 2006CB601202, 2006CB601204);the National 111 Project of China (Grant No. B06024);US Office of Naval Research (Grant No. N000140210117);the National Natural Science Foundation of China (Grant Nos. 10572111, 10632060);the National H-Tech Research and Development Program of China (Grant No. 2006AA03Z519)

摘　　要：Open-celled metal foams fabricated through metal sintering offers novel mechani- cal, thermal and acoustic properties. Previously, polymer foams were used as a means of absorbing acoustic energy. However, the structural applications of these foams are inherently limited. The metal sintering approach provides a cost-effective means for the mass-production of open-cell foams from a range of materials, in- cluding high-temperature steel alloys. The low Reynolds number fluid properties of sintered steel alloy (FeCrAlY) foams were investigated in a previous study. The static flow resistance of the foams was modeled based on a cylinder and a sphere arranged in a periodic lattice at general incidence to the flow, with the resulting predictions correlating well to measurements. The application of the flow resis- tance in an acoustic model is the primary focus of the present study. The predic- tions for the static flow resistance of the sintered foams are first used in a theo- retical model to determine the characteristic impedances, as well as the propaga- tion constants of the foams. Subsequently, the predicted acoustic performance of the foams is compared to experimental results. Finally, the design space for a simple acoustic absorber incorporating sintered foams is examined, with the ef- fects of absorber size, foam selection, and foam spacing explored.Open-celled metal foams fabricated through metal sintering offers novel mechani- cal, thermal and acoustic properties. Previously, polymer foams were used as a means of absorbing acoustic energy. However, the structural applications of these foams are inherently limited. The metal sintering approach provides a cost-effective means for the mass-production of open-cell foams from a range of materials, in- cluding high-temperature steel alloys. The low Reynolds number fluid properties of sintered steel alloy (FeCrAlY) foams were investigated in a previous study. The static flow resistance of the foams was modeled based on a cylinder and a sphere arranged in a periodic lattice at general incidence to the flow, with the resulting predictions correlating well to measurements. The application of the flow resis- tance in an acoustic model is the primary focus of the present study. The predic- tions for the static flow resistance of the sintered foams are first used in a theo- retical model to determine the characteristic impedances, as well as the propaga- tion constants of the foams. Subsequently, the predicted acoustic performance of the foams is compared to experimental results. Finally, the design space for a simple acoustic absorber incorporating sintered foams is examined, with the ef- fects of absorber size, foam selection, and foam spacing explored.

关 键 词：metal foam SOUND ABSORPTION modeling experiment ACOUSTIC design 

分 类 号：TF125.6[冶金工程—粉末冶金]