ON ACOUSTIC PERFORMANCE OF MEASURING STRUCTURE FOR CAVITATION NOISE  

作　　者：Wu, Jian-hua  Chai, Gong-chun  Wang, He-sheng 

机构地区：[1] Nanjing Hydraulic Research Inst, Nanjing, China

出　　处：《Journal of Hydrodynamics》1991年第2期42-50,共9页水动力学研究与进展B辑（英文版）

摘　　要：The acoustic performance of the structure for measuring cavitation noise is theoretically analysed, and two judging criteria of the acoustic performance of STW (sound transmission window) are presented in this paper. One is of impedance matching between working liquid and STW:ρ1C1 = ρ2C2. The other is of maximum frequency (or minimum wave length) of cavitation noise spectrum: fmax&le c/60D (or λmin/D ≥ 60). If either of the criteria is met reliable measured results of cavitation noise will be obtained. The theoretical results are verified through experiments. According to the criteria, the paper analyses the acoustic performance of routinely used plexiglass STW. The results show that in the research of clear water cavitation the impedance ratio, 2. 18, does not satisfy ρ1C1 = ρ2C2, and fmax&le C/60D hardly holds for actual cavitation noise spectrum. Therefore, plexiglass STW is not good enough for sound transmission. From this point of view, polyethylene is better sound transmission material than plexiglass.The acoustic performance of the structure for measuring cavitation noise is theoretically analysed, and two judging criteria of the acoustic performance of STW (sound transmission window) are presented in this paper. One is of impedance matching between working liquid and STW:ρ1C1 = ρ2C2. The other is of maximum frequency (or minimum wave length) of cavitation noise spectrum: fmax&le c/60D (or λmin/D ≥ 60). If either of the criteria is met reliable measured results of cavitation noise will be obtained. The theoretical results are verified through experiments. According to the criteria, the paper analyses the acoustic performance of routinely used plexiglass STW. The results show that in the research of clear water cavitation the impedance ratio, 2. 18, does not satisfy ρ1C1 = ρ2C2, and fmax&le C/60D hardly holds for actual cavitation noise spectrum. Therefore, plexiglass STW is not good enough for sound transmission. From this point of view, polyethylene is better sound transmission material than plexiglass.

关 键 词：Acoustic Waves Transmission GLASS Acoustic Properties HYDRODYNAMICS Fluid Structure Interaction POLYETHYLENES Acoustic Properties Water Waves 

分 类 号：TV131.2[水利工程—水力学及河流动力学]