Jafari Mohammad Javad, Monazam Mohammad Reza, Kazempour Marzieh
1Environmental and Occupational Hazards Control Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
2Department of Occupational Health Engineering, School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
J Environ Health Sci Eng. 2018 Sep 21;16(2):289-297. doi: 10.1007/s40201-018-0317-3. eCollection 2018 Dec.
Noise is definitely a nuisance to the quality of people's lives and health. In recent decades the public has suffered from industrial and environmental noise and its control has had a desirable impact on people's lives. Though noise cannot be completely eliminated, it can be mitigated to a level that it is less harmful to people's health. One of the ways for obtaining these pleasing environment is to design and use the absorbing sound materials. Fibrous and porous materials are the ordinary absorptive materials that are not good absorbers for low and mid frequency sounds. In this study, we examined the different parameters that affect the quality of absorbers, which could provide the best pattern for mid to low frequencies with the numerical and analytical models. For this purpose, three methods including measurement of absorption coefficient by impedance tube, analytical and numerical methods were used. Accuracy was determined by comparing measurement and two prediction methods. The results showed that the experimental and analytical methods provided by the Delany and Bazely and finite element (COMSOL) modeling have good adaptation. The best thickness of porous sound absorbers for low to mid frequencies f:[80-5000]Hz is about 10 cm with the air flow resistivity of 10,000-30,000 Ns/ m.
噪音无疑是影响人们生活质量和健康的一大公害。近几十年来，公众深受工业和环境噪音之苦，而对其进行控制已对人们的生活产生了有益影响。尽管噪音无法完全消除，但可以将其减轻到对人们健康危害较小的程度。实现这种宜人环境的方法之一是设计和使用吸音材料。纤维状和多孔材料是常见的吸音材料，但它们对低频和中频声音的吸收效果不佳。在本研究中，我们研究了影响吸音材料性能的不同参数，通过数值和分析模型为中低频提供最佳模式。为此，采用了三种方法，包括用阻抗管测量吸收系数、分析方法和数值方法。通过比较测量结果和两种预测方法来确定准确性。结果表明，由德拉尼和巴泽利提供的实验和分析方法以及有限元（COMSOL）建模具有良好的适应性。对于80至5000赫兹的低频到中频，多孔吸声器的最佳厚度约为10厘米，气流阻力为10000至30000牛秒/立方米。
