空间卷曲超表面圆柱壳声波调控及试验研究

Acoustic wave control and experimental study on space curled meta-surface cylindrical shell

基于广义斯涅尔定律,设计了两种由空间卷曲单元构成的空间卷曲超表面圆柱壳,通过改变单元内部齿条长度、宽度以及数量改变声波传播路径的长度和透射声波相位,实现对点声源声波的单向调控和双向调控,在目标范围内产生低噪声区域。推导了适用于超表面圆柱壳的极坐标广义斯涅尔定律表达式,应用有限元方法分析了空间卷曲超表面圆柱壳在点声源作用下的声压场分布和波的调控特性。搭建了声压测试试验平台,测得结构的透射声场声压值,将测量值与数值结果对比验证,两者具有较好的一致性。结果表明所设计的超表面圆柱壳可实现对柱面波的有效调控,为管道、压力容器等工程结构产生的柱面波噪声控制提供有益参考。

Here,based on the generalized Snell’s law,2 types of space curled meta-surface cylindrical shells composed of space curled elements were designed.By changing length,width and number of internal gear racks in elements to change length of acoustic wave propagation path and phase of transmitted acoustic wave,unidirectional and bidirectional controls of point sound source acoustic wave was realized to generate a low noise area within target range.The polar coordinate generalized Snell’s law expression applicable to meta-surface cylindrical shell was derived,and the finite element method was used to analyze sound pressure field distribution and wave control characteristics of space curled meta-surface cylindrical shell under action of a point sound source.A sound pressure testing experimental platform was built to measure structures’transmitted sound field sound pressure values.The measured values were compared with numerical results,and both of them agreed better with each other.The results showed that the designed meta-surface cylindrical shells can effectively regulate cylindrical waves to provide a useful reference for controlling cylindrical wave noise generated by engineering structures of pipelines and pressure vessels.