微型消声器特性及其测量方法的研究

发布时间：2018-02-23 02:07

本文关键词： 传声损失阻抗管 LabVIEW 传声器　出处：《合肥工业大学》2014年硕士论文　论文类型：学位论文

【摘要】：冰箱的噪声是衡量冰箱性能品质的重要指标之一,冰箱压缩机是冰箱的主要噪声源,对冰箱整机噪声的水平有很大的影响。其中压缩机消声器的消声性能的好坏直接关系到压缩机噪声的大小,消声器的传声损失是衡量消声器消声性能的重要参数。因此设计一套微型消声器传声损失的测量系统,用来准确的判定微型消声器的消声性能,对于微型消声器结构的设计与选择具有十分重要的意义。本文对微型消声器的评价指标以及测量方法进行分析研究,总结出消声器传声损失测量的四种方法,对其测量原理和测试步骤进行分析,然后对四种测量方法的优缺点,进行总结,归纳出每种方法的适用条件。通过对比,本文这里采用传递矩阵法的原理进行测量。在硬件方面,本文参照相关的国家标准,结合实际的工程应用,设计了一套阻抗管,能够适应不同频段消声器传声损失的测量,并且确定了阻抗管的长度和壁厚、传声器间距及位置、试件套筒、支撑架、扬声器等结构参数。在软件方面,本文以阻抗管中消声器传声损失测量的传递矩阵法为测量原理,采用LabVIEW软件,编写出一套微型消声器传声损失的测量系统,该系统完成了信号发生、传声器校准、数据采集、数据分析与处理以及结果保存等程序模块的编写,能够实现传声损失准确且快速的测量。本文在宽频声源激励下,将测得的传声损失结果和在virtual lab软件中的仿真结果进行对比,结果相差不大,并且在相同频率段传声损失曲线的趋势保持一致,说明该系统准确、有效。最后对传声损失的测量误差进行研究,在传声器间距不同的条件下,利用该系统测量,通过对比,分析讨论传声器间距对测量结果的影响,同时讨论平均方式、系统频率分辨率和分析谱线数对测量误差的影响。
[Abstract]:The noise of the refrigerator is one of the important indexes to measure the performance and quality of the refrigerator. The compressor of the refrigerator is the main noise source of the refrigerator. It has a great influence on the noise level of the whole refrigerator. The noise performance of the compressor muffler is directly related to the noise level of the compressor. The sound transmission loss of the muffler is an important parameter to measure the noise performance of the muffler. Therefore, a measuring system for the sound transmission loss of the miniature muffler is designed, which is used to accurately judge the muffling performance of the miniature muffler. It is of great significance for the design and selection of miniature muffler structure. In this paper, the evaluation index and measurement method of miniature muffler are analyzed, and four methods for measuring sound transmission loss of muffler are summarized. The measuring principle and steps are analyzed, and the advantages and disadvantages of the four measuring methods are analyzed. Through comparison, the principle of transfer matrix method is used to measure. In terms of hardware, referring to the relevant national standards and combining with practical engineering applications, a set of impedance tubes is designed, which can be used to measure the sound transmission loss of mufflers in different frequency bands, and the length and wall thickness of the impedance tubes are determined. Microphone spacing and location, test sleeve, support frame, loudspeaker and other structural parameters. In the aspect of software, taking the transfer matrix method of acoustic loss measurement of muffler in impedance tube as the measuring principle, using LabVIEW software, a set of measurement system of sound transmission loss of miniature muffler has been compiled, and the system has completed the signal generation. The program modules, such as microphone calibration, data acquisition, data analysis and processing, and result preservation, can realize accurate and fast measurement of sound transmission loss. In this paper, under the excitation of wide-band sound source, the result of sound transmission loss measured is compared with the result of simulation in virtual lab software. The result is not different, and the trend of sound loss curve in the same frequency band is consistent, which shows that the system is accurate. Effective. Finally, the measurement error of sound transmission loss is studied. Under the condition of different microphone spacing, the influence of microphone spacing on the measurement results is analyzed and discussed by using the system, and the average method is discussed at the same time. The influence of system frequency resolution and the number of spectral lines on the measurement error.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB535.2

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