宽带低反射式通风声屏障

发布时间：2018-04-06 03:23

本文选题：声子晶体　切入点：能带结构　出处：《南京大学学报(自然科学)》2017年01期

【摘要】：提出了一种基于长方晶格型声子晶体结构的波矢调制特性的声屏障设计机理.该声屏障能够以极低的反射率将入射声波导引至内部,并在相对于原有的传播方向偏移一定距离后出射,从而产生局部的声静区.由于该机理不依赖于粘滞吸收效应或负的等效声学参数,因而可保证出射声波的强度及波形均与入射声波相近,使得所设计的声屏障能够在隔声的同时有效地将入射声能量导引至预设的位置进行吸收或进一步利用,并且具有较宽的工作频带.数值计算结果证明在7750~10000Hz频率范围内均有35dB左右以上的隔声量,最大隔声量可达50dB.此外,区别于传统重墙隔声,声子晶体薄板在隔声时未导致背景媒质的阻断,留有与声波波长同尺度的间隙.这些特性对于在实际隔声问题中的应用具有重要价值.
[Abstract]:A sound barrier design mechanism based on the wave vector modulation characteristics of rectangular lattice phonon crystal structure is proposed.The acoustic barrier can guide the incident sound waves to the interior at a very low reflectivity, and move out at a certain distance relative to the original direction of propagation, thus producing a local acoustic static region.Since the mechanism does not depend on the viscous absorption effect or negative equivalent acoustic parameters, the intensity and waveform of the emitted sound wave can be guaranteed to be close to the incident sound wave.The designed sound barrier can effectively direct the incident sound energy to the preset position for absorption or further utilization while isolating the sound, and has a wide operating band.The numerical results show that in the range of 7750~10000Hz frequency, there is sound insulation above 35dB, and the maximum sound insulation is up to 50 dB.In addition, different from the traditional heavy wall sound insulation, the phonon crystal thin plate does not lead to the blocking of the background media in the sound insulation, leaving a gap with the acoustic wave wavelength of the same scale.These characteristics are of great value for the practical application of sound insulation.
【作者单位】：南京大学声学研究所;人工微结构科学与技术协同创新中心;
【基金】：国家自然科学基金(11634006;81127901) 中兴通讯产学研合作基金
【分类号】：O42

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