摘要
以烧结金属纤维多孔材料为研究对象，对其在不同温度（20～500℃）和温度梯度（-2．4℃／mm，＋4．05℃／mm）作用下的吸声性能进行了理论计算和分析．应用双传声器传递函数法原理，设计并搭建了多孔金属材料高温吸声性能实验的测试装置，对材料在不同温度点下的吸声性能进行了实验测试，初步验证了理论计算的正确性．研究表明，采用参考温度法能够较好地计算温度较低时的材料吸声性能，温度的变化对多孔金属材料表面声阻抗率具有显著影响．当存在温度梯度场作用时，应重视温度梯度对多孔金属材料总体吸声性能的影响，在一定条件下，负温度梯度可以提高材料的吸声性能，而正温度梯度可使材料吸声性能趋于降低．
Focusing the attention on a sintered fibrous metal sample, the sound absorption properties under different temperatures （from 20 ℃ to 500 ℃） and temperature gradients（-2.4 ℃/ mm and 4.05 ℃/mm） are theoretically evaluated. By adopting the two-microphone transfer-function method, a set for measuring the uniform high-temperature sound absorption properties of porous metal is developed, and the sound absorption properties of a sintered fibrous metal sample at different temperatures are measured to validate the theoretical results. It is found that reference-temperature method can be used to well evaluate the porous metal acoustic properties at relatively low temperatures. And the changes of temperature fields exert remarkable effects on the surface acoustic impedance at normal incidence of material. When the constant temperature gradient exists across the material cross-section, the effects of temperature gradient on overall sound absorption characteristics of porous metal ought to be regarded considerably. Under certain conditions, the minus temperature gradient may enhance the sound absorption of porous metal whereas the positive temperature brings an adverse effect.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2008年第11期1327-1331,共5页
Journal of Xi'an Jiaotong University
基金
国家重点基础研究发展规划资助项目(2006CB601204)
国家自然科学基金重点资助项目(10632060)
关键词
烧结金属纤维
多孔金属材料
温度梯度
吸声
sintered fibrous metal
porous metallic material
temperature gradient
sound absorption
