高声强声源及其应用

本文介绍了４种高声强声源：１．单孔旋转阀；２．带中心杆的哈特曼发声器阵；３．喷流点声源；４．喷流反馈旋转发声器。本文还给出４种声源的用途，即分别应用于：１．流动管道中有限振辐波的传播研究；２．进气道吸声内衬的声阻抗测量技术；３．风洞声学环境的研究；４．利用高强的能来清灰除尘。

强声源对低频主动拖线阵声纳的干扰效果研究

针对低频主动拖线阵声纳通过发射低频声信号对水下目标进行探测这一特性,提出了使用强声源对低频主动拖线阵声纳实施压制性干扰的方法,并对影响强声源干扰效果的因素进行了仿真分析。结果表明,在综合考虑这些影响因素的前提下,使用该方法能够达到较好的干扰效果。

射流反馈旋转发声器的研究

用声能进行消灰除尘是噪声控制的一个新的领域。研究的关键是设计出一种既具有高声强又具有低频率的发声器。本文通过自行设计的射流反馈旋转发声器的实验研究。表明：（１）该发声器可以提供高达１４０ｄＢ的强声。（２）作为清灰除尘系统的核心部件。该声源在频谱上显示出良好的低频特性。（３）该发声器具有实用性，因为它可以在低耗气量和低的工作压力下工作。（４）导声管具有增强低频声的效果。

声波解堵提效技术在尿素热解炉上的应用

针对燃煤机组选择性催化还原脱硝系统尿素热解炉堵塞问题,以华电国际电力股份有限公司十里泉发电厂2×600MW燃煤机组为例,在声波解堵提效技术原理的基础上,根据电厂实际情况提出了在热解炉进口热风烟道布置可调频高声强声源的声波解堵提效改造方案。性能测试及实际应用表明,声波解堵系统投运后脱硝系统热解炉未再出现堵塞现象。

Investigation on Major Noise Sources of Vehicle Diesel Engine Based on Sound Intensity Measurement

In order to reduce the noise and vibration of the diesel engine,it is crucial to exactly identify the engine noise source character.Based on "two-microphone" method,the sound intensity measurement of a vehicle four-stroke diesel engine was carried out in a hemi-anechoic chamber.Then the sound intensity contour maps were obtained from the measurement results and the main noise components of different frequencies on all the measurement surfaces were picked out to construct contour maps.By analysizing the relationship between the characteristics of contour maps and the space distribution of the engine compartment,the major sources of the exterior radiation noise of the diesel engine were identified.The results provided a creditable basis for improving the noise performance of the engine in the next phase.