低频消声周期管路设计及其声学性能测试  

Design of a low-frequency noise suppression periodic pipe and its acoustic performance test

作　　者：沈惠杰[1] 张涛[1] 汤智胤[1] 郁殿龙[2] SHEN Huijie;ZHANG Tao;TANG Zhiyin;YU Dianlong(College of Power Engineering,Naval University of Engineering,Wuhan 430033,China;Science and Technology on Integrated Logistics Support Laboratory,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]海军工程大学动力工程学院,武汉430033 [2]国防科技大学装备综合保障技术重点实验室,长沙410073

出　　处：《振动与冲击》2022年第8期79-85,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(51705529)。

摘　　要：为控制船舶空调通风管路系统的低频噪声传播,设计了多个Helmholtz消声器周期安装、具有低频消声特性的空调通风管路。该管路上等间距开有多个螺纹孔座,Helmholtz消声器可以选择不同的安装间距通过颈管的外螺纹与螺纹孔座配合安装于空调通风管路上,形成不同晶格常数的周期管路。对周期管路的声传播特性进行数值计算,从理论预测了所设计周期管路中可抑制声传播带隙的存在,同时给出了带隙的精确耦合条件。进一步,测试了周期管路的减噪量(noise reduction,NR)和插入损失(insertion loss,IL)。计算结果和实测结果表明,设计的声学周期管路确实存在局域共振带隙和布拉格带隙,带隙频率范围内可有效抑制管内声波传播。此外,这两种带隙位置可由安装间距进行调节,在一定条件下,两种带隙相邻带边可相互接合,形成耦合带隙。耦合带隙显著改善耦合前布拉格带隙的声衰减性能,与局域共振带隙耦合形成具有低频、宽带、强衰减的声衰减带,能有效衰减管内低频空气噪声传播,达到船舶空调通风管路系统低频噪声降噪的目的。To control the transmission of low-frequency noise in the ventilation and air conditioning pipelines,a periodic pipe equipped with a 1D array of Helmholtz mufflers was constructed.Such a periodic pipe has a set of screw holes distributed in the axial direction with identical spacing such that the Helmholtz mufflers could be seated into the holes via the matching screw on the Helmholtz neck,thereby forming periodic pipes with various lattice constants.Numerical simulation results show that there are two types of low-frequency band gaps existed in the periodic pipe system,i.e.,the resonant and the Bragg type band gaps,respectively.These two types of gaps can be coupled by modulating the geometric parameters e.g.,the lattice constant,via an exactly coupling condition.The experimental test of noise reduction(NR)and insertion loss(IL)further validate the theoretical prediction.Experimental results show that within the band gap frequency ranges,the propagation of acoustic waves in the periodic system will be prohibited,exhibiting a good suppression effect on the transmission of low-frequency pipe noise,particularly in the resonant gap frequency range.Moreover,increasing the installing space of Helmholtz mufflers,the Bragg type gap will be moved towards the lower frequency range.Under a certain condition,the Bragg and the resonant gaps could be combined together,giving rise to a low-frequency and broadband coupled gap with heavy attenuation effect.The experiment test reveals that the proposed strategy possesses a good control effect on the low-frequency noise transmission in the ventilation and air conditioning pipeline,thus providing a possible technical way to deal with the low-frequency noise problem in ship ventilation and air conditioning pipeline systems.

关 键 词：管路低频噪声 声学超材料 传递损失(TL) 插入损失(IL) 减噪量(NR) 

分 类 号：TH212[机械工程—机械制造及自动化] U664[交通运输工程—船舶及航道工程]