气固两相流介质中声衰减测量方法研究-声学技术.PDF

第 28 卷第 1 期 声 学 技 术 Vol.28, No.1 2009 年 2 月 Technical Acoustics Feb., 2009 气固两相流介质中声衰减测量方法研究 安连锁，杨文泽，武国红，卢 晓，刘铭媛，姜根山 （华北电力大学能源与动力工程学院，河北保定，071003 ） 摘要：通过声波衰减谱反推气固两相流状态，是气固两相流声学监测研究的一种重要方法。在假设声能量的相对衰 减量与声波传播距离成正比的前提下，推导出声压级随传播距离变化的表达式。设计搭建了测试两相流下声衰减的 实验台，根据声压级随传播距离变化的关系，推导出实验计算气固两相流声衰减系数的表达式。实验条件下的噪声 主要为风机的漩涡噪声和旋转噪声，以及机械噪声和气流的气动噪声。分析不同噪声的特点，提出了通过 A 计权网 络和小波滤波相结合的滤除噪声的方法。 关键词：气固两相流；声衰减；背景噪声 中图分类号：P733 文献标识码：A 文章编号：1000-3630(2009)-01-0006-04 A study of acoustical attenuation measurement in gas-solid two-phase flow AN Lian-suo, YANG Wen-ze, WU Guo-hong, LU Xiao, LIU Ming-yuan, JIANG Gen-shan (School of Energy and Power Engineering, North China Electric Power University, Baoding 071003, Hebei, China) Abstract: Deducing the state of gas-solid two-phase flow from acoustic attenuation spectrum is an important approach to acoustic monitor and study of gas-solid two-phase flow. The expression of sound pressure level associated with propagation distance is deduced by assuming that the relative attenuation amount of sound energy is proportional to sound propagation distance. The experimental apparatus for measuring acoustic attenuation in gas-solid two-phase flow is established. According to the expression of sound pressure level, the expression for calculating acoustic attenuation index of gas-solid two-phase flow is also obtained. The background noise in experiments is mainly the noise caused by fans’ vortex and rotation, as well as the mechanical noise and aerodynamic noise. The characteristics of different noise are analyzed, and the method of eliminating noise is proposed, by using A-weighting network and wavelet fil