充液背腔板式水动力噪声消声器参数分析

Parameter analysis on hydrodynamic noise plate-silencer with fluid cavity

弹性板式结构具有良好的消声性能,在低频宽带消声性能上有优于传统的共振腔式抗性或多孔吸声材料阻性被动消声器的潜力。文章计算分析了弹性板及其背腔几何和材料参数对消声器性能的影响。研究表明:弹性板一阶固有频率越低其低频消声性能越好,因此应选择较大面积弹性板、低刚度质量比的弹性板材料;充液背腔对弹性板约束越小,弹性板弹性振动越强烈,板振动引起的声反射效果越好,因此空气背腔低频宽带消声性能优于充水背腔。在实现相同低频宽带消声性能的情况下,空气背腔尺寸相对于充水背腔更为紧凑,适用于消声器允许安装空间较小的环境。此外,通海水管路系统工作于不同水深条件,背腔充气压力应与管内背景压力持平;对不同充气压力下消声性能的计算对比显示:充气背腔消声器在大背景压力下仍能获得良好的低频宽带消声性能,且由于背腔空气附加质量影响低频消声性能略有提升。

Plate-silencer possesses low frequency and broadband noise attenuation characteristics, which is potentially better than conventional holmholtz resonators and porous sound absorbing materials. In this paper, material and geometric coefficients of plate and cavity are analyzed. The study shows that the less cavity restraining on plate is, the more effective silencers is and the lower plate first resonate frequency is, the lower noise attenuation frequency is. Therefore, low spring-mass-ratio plate with large area is preferred;more compact geometric silencer can be realized with air cavity other than water cavity for retaining low frequency and broadband noise attenuation characteristics. Influence of pressured air cavity on TL is an-alyzed and the results indicate that plate silencers retain low frequency broadband noise attenuation char-acteristics under higher pressure conditions, and the noise attenuation broadband expanded and shift to low frequency.