水下排气降噪装置设计及其降噪特性  

Design of underwater exhaust noise reduction device and its noise reduction characteristics

作　　者：张凌[1] 邢允 叶豪杰 吴大转[1] ZHANG Ling;XING Yun;YE Hao-jie;WU Da-zhuan(College of Energy Engineering,Zhejiang University,Hangzhou 310027,China)

机构地区：[1]浙江大学能源工程学院,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2021年第7期1381-1390,共10页Journal of Zhejiang University：Engineering Science

摘　　要：为了降低水下排气过程中难以衰减的中低频气泡噪声和边界噪声,从排气噪声特性和机理出发,设计由排气层、挡板层和纱网层组成的水下排气降噪装置.装置结合多小孔低速排气、噪声隔绝和两相接触面积增加等降噪方法,将高速排气气流转化为低速气泡流,有效降低水下排气噪声.实验结果表明:装置在实验流量范围内可以有效降低水下排气噪声,全频段噪声降低7.5 dB,其中噪声低频段(10~250 Hz)能量占比最大降低18.7%,极大缓解了噪声能量在低频段的富集;装置的排气层起主要降噪作用,其与挡板层组合而成的装置具有最好的、最稳定的低频降噪效果.An underwater exhaust noise reduction device consisting of an exhaust layer,a baffle layer and a gauze layer was designed based on the characteristics and mechanism of underwater exhaust noise,in order to reduce the medium-low frequency bubble noise and boundary noise that is difficult to attenuate during underwater exhaust.The device combines noise reduction methods like low-speed exhaust with multiple small holes,noise isolation and increasing two-phase contact area to convert the high-speed exhaust air flow into a low-speed bubble flow,effectively reducing underwater exhaust noise.Experimental result shows that the device reduces the underwater exhaust noise effectively within the experimental flow rate range.The noise reduction in the full frequency band is about 7.5 dB,and the energy ratio of the low frequency band(10~250 Hz)is reduced by a maximum of 18.7%,greatly alleviating the enrichment of noise energy in low frequency band;moreover,the exhaust layer plays a major role in noise reduction,and its combination with baffle layer reduces low-frequency exhaust noise the best and the most stably.

关 键 词：水下排气 中低频噪声 降噪装置设计 多孔排气降噪 降噪性能 

分 类 号：TB535[理学—物理]