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一种基于贴附型Helmholtz 共鸣器的声学超材料的隔声性能研究（英文）Study on Sound Insulation Performance of Acoustic Metamaterials based on Adhesive Helmholtz ResonatorAbstractAcoustic metamaterials have attracted great attention for their excellent sound insulation performance. This paper focuses on the study of an acoustic metamaterial based on an adhesive Helmholtz resonator, aiming to improve the sound insulation performance of building materials. The morphology and characteristics of the acoustic metamaterial are analyzed by theoretical modeling and experimental measurement. The results show that the acoustic metamaterial has a significant effect on sound insulation, reducing the sound transmission loss of the building material. The acoustic metamaterial can be applied to various sound insulation applications.Keywords: acoustic metamaterials, sound insulation, Helmholtz resonator, adhesiveIntroductionWith the rapid development of economy and technology, the level of noise pollution is increasing, which brings serious harm to human health and environment. Acoustic metamaterials are materials that have special physical structures, which can achieve extraordinary acoustic properties that are not found in natural materials. They have attracted the attention of scientists because of their excellent sound insulation performance and potential applications in fields such as building materials, vehicle noise reduction, and communication systems.The Helmholtz resonator is a classical acoustic resonator that consists of a cavity with a small neck that connects to the outside. Helmholtz resonators have been used as sound absorbers and silencers for many years, and their excellent sound insulation properties have been well studied. In recent years, researchers have explored the use of the Helmholtz resonator as a building block for the construction of acoustic metamaterials.This paper proposes an acoustic metamaterial based on an adhesive Helmholtz resonator, which has excellent sound insulationperformance. We analyze the morphology and characteristics of the acoustic metamaterial through theoretical modeling and experimentalmeasurement, and discuss the factors affecting the sound insulationperformance of the metamaterial.Materials and MethodsThe acoustic metamaterial is composed of a matrix material andadhesive Helmholtz resonators. The matrix material is made of cementwith a density of 2480 kg/m3, while the adhesive Helmholtz resonators are made of a 5cm thick polyurethane foam, with a neck diameter of2cm and a depth of 3cm. The thicknesses of the neck and cavity are designed to achieve maximum sound insulation performance.The acoustic metamaterial is prepared by mixing the matrix material and the adhesive Helmholtz resonators in different proportions and then casting the mixture into rectangular molds with a size of 30cm x 30cm x 5cm. The specimens are then cured for 28 days in a standard curing room with a temperature of 20 ± 2°C and a relative humidity of 60 ± 5%.The sound insulation performance of the acoustic metamaterial ismeasured by using a sound transmission loss (STL) test. The test is conducted according to ASTM E90-09, with a loudspeaker as the sound source and a microphone as the receiver. The sound source is located on one side of the specimen, while the receiver is located on the other side. The sound pressure level (SPL) is measured at different frequencies, and the STL is calculated as the difference between the SPL on the source side and the SPL on the receiver side.Results and DiscussionThe theoretical modeling shows that the adhesive Helmholtzresonators have a strong absorption effect on sound waves with a frequency range of 200-500Hz. The STL measurement results show that the sound insulation performance of the acoustic metamaterial is closely related to the proportion of the adhesive Helmholtz resonators in the matrix material, and the maximum STL value is achieved when the proportion is 15%.The maximum STL of the acoustic metamaterial is 48.3dB at afrequency of 315Hz, which is much higher than that of the plain cementmatrix material, whose maximum STL is only 29.7dB at the samefrequency. This shows that the adhesive Helmholtz resonators significantly improve the sound insulation performance of the matrixmaterial. The STL of the acoustic metamaterial gradually decreases with increasing frequency, which is consistent with the theoretical modeling.ConclusionAn acoustic metamaterial based on an adhesive Helmholtz resonator is proposed in this paper, and its sound insulation performance is studied through theoretical modeling and experimental measurement. The results show that the acoustic metamaterial has excellent sound insulation performance in the frequency range of 200- 500Hz, and its sound transmission loss is much higher than that of plain cement matrix material. The study provides a basis for the application of acoustic metamaterials in sound insulation of building materials, and further exploration of the potential of Helmholtz resonators in the construction of acoustic metamaterials.。
高强度Helmholtz声源的声学特性研究乔正辉;董卫;程梅;周树青【摘要】为研究Helmholtz声源的声学特性,设计并制作了一款由扬声器和Helmholtz共振器组成的Helmholtz声源,并对其等效声阻抗、两端电压、输出声压值和电声转换效率随信号频率变化的响应特性进行了初步探索.结果表明,Helmholtz声源的声学特性与扬声器和Helmholtz共振器的相互作用有关, Helmholtz声源的声学阻抗特性主要由Helmholtz共振器决定;扬声器的谐振或Helmholtz共振器的共振能够增强Helmholtz声源的声波辐射能力,可以有效提高声源的电声转换效果;在选定的实验条件下, Helmholtz声源的最大输出声压值约是扬声器的22倍,此时Helmholtz声源的电声转换效率高达113%.%To research the acoustic characteristics of Helmholtz sound source(HSS),a HSS combined a loudspeaker with a HR was designed and fabricated. With the changes of signal frequencies,the response characteristics of HSS,including equivalent acoustic impedances,terminal voltages,output sound pressures and electro-acoustic efficiencies,were preliminarily explored through numerical simulations and experiments. Results show that the acoustic characteristics of HSS are related to the interactions between loudspeaker and HR,and the equivalent acoustic impedance characteristics of HSS are dominated by HR. The resonances of both loudspeaker and HR may strengthen sound radiation and thus improve electro-acoustic efficiency of HSS. Under selected experimental conditions,the maximum output sound pressure of HSS may be 22 times of that generated byloudspeaker,thereby the electro-acoustic efficiency reaches up to 113%.【期刊名称】《中国机械工程》【年(卷),期】2018(029)010【总页数】7页(P1186-1192)【关键词】扬声器;Helmholtz共振器;共振;声压;电声转换效率【作者】乔正辉;董卫;程梅;周树青【作者单位】东南大学能源与环境学院,南京,210096;东南大学能源与环境学院,南京,210096;东南大学能源与环境学院,南京,210096;东南大学能源与环境学院,南京,210096【正文语种】中文【中图分类】TB540 引言近年来，声波控制细颗粒物的研究逐渐成为热点。
基于Hilbert-Huang变换的雷达信号特征提取技术
吕建慧;席泽敏;卢建斌;刘江波
【期刊名称】《雷达科学与技术》
【年(卷),期】2009(7)5
【摘要】针对高分辨雷达目标散射回波的非平稳特性,提出了利用Hilbert-Huang 变换进行时频分析获得目标特性的方法.首先利用简单电磁散射模型仿真了三类目标的一维距离像,然后采用Hilbert-Huang变换对各类目标在不同姿态角下的回波进行时频分析,提取时频分布图的边际谱作为目标特征矢量,利用径向基函数神经网络分类器对特征矢量进行训练和学习,最后对三类目标作了识别,仿真对比实验验证了该方法的有效性.
【总页数】7页(P339-344,348)
【作者】吕建慧;席泽敏;卢建斌;刘江波
【作者单位】海军工程大学电子工程学院,湖北武汉,430033;海军工程大学电子工程学院,湖北武汉,430033;海军工程大学电子工程学院,湖北武汉,430033;海军工程大学电子工程学院,湖北武汉,430033
【正文语种】中文
【中图分类】TN957.52
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1.基于Hilbert-Huang变换的变压器局部放电信号特征提取 [J], 宋峰;陈军
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3.基于Hilbert-Huang变换的雷达发射机故障特征提取 [J], 王刘军;刘昌锦
4.基于Hilbert-Huang变换的探地雷达信号增强及复信号分析 [J], 冯德山;余凯;戴前伟
5.基于Hilbert-Huang变换的水声信号特征提取及分类技术 [J], 王锋;尹力;朱明洪
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基于螺旋线的紧凑型高压纳秒脉冲发生器
潘亚峰;张喜波;刘胜
【期刊名称】《强激光与粒子束》
【年(卷),期】2017(029)002
【摘要】提出了一种结合高耦合Tesla变压器和螺旋形成线(FL)的紧凑型高压纳秒脉冲发生器,由内置Tesla变压器充电的螺旋FL包含外屏蔽筒、螺旋中筒和内导体筒,内外筒的两端均短路连接,螺旋中筒的一端开路,另一端穿过内外简短路端面并与主开关电极连接.该结构简单紧凑、易于实现,输出脉冲前沿快、平顶好.给出了一组10 GW功率、百ns脉宽的FL设计,采用Midel 7131合成酯绝缘介质,FL外筒内径0.88 m,长度2 m.
【总页数】5页(P63-67)
【作者】潘亚峰;张喜波;刘胜
【作者单位】西北核技术研究所,高功率微波技术重点实验室,西安710024;西北核技术研究所,高功率微波技术重点实验室,西安710024;西北核技术研究所,高功率微波技术重点实验室,西安710024
【正文语种】中文
【中图分类】TN782
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Janus-Helmholtz水声换能器理论问题研究桑永杰;蓝宇【摘要】In this paper, the reason for increase of the longitudinal resonant frequency of a Janus transducer in water are analyzed through the equivalent circuit of Janus-Helmholtz underwater acoustic transducer by taking into account mutual radiation in order to solve the theoretical questions on Janus-Helmholtz acoustic transducer. The mechanism of broadband transmitting of Janus-Helmholtz underwater acoustic transducers is obtained by analyzing phase fre-quency curves of the vertical vibration and liquid cavity vibrations. The influence of cavity wall's elasticity on acous-tic performance of Helmholtz resonator is researched. A prototype that operates in the band between 1 kHz and 3 kHz is designed. Test results showed that the vibration and acoustic characteristics of the prototype are consistent with the theoretical research results.%为了解决Janus-Helmholtz水声换能器研究中的理论问题,通过互辐射模型时的Janus-Helmholtz水声换能器等效电路,分析了Janus换能器纵振动谐振频率在水中升高的原因;通过对Janus换能器纵振动和液腔振动的相频曲线的分析,得出了Janus-Helmholtz水声换能器宽带发射的机理,研究了腔体弹性对Helmholtz声学性能的影响规律. 设计了工作频段为1~3 kHz的Janus-Helmholtz换能器试验样机,样机的测试结果表明其振动及声学特性与理论研究结果相符.【期刊名称】《哈尔滨工程大学学报》【年(卷),期】2015(036)007【总页数】5页(P906-910)【关键词】Janus-Helmholtz换能器;等效电路;宽带;互辐射;声源级【作者】桑永杰;蓝宇【作者单位】哈尔滨工程大学水声技术重点实验室,黑龙江哈尔滨150001;哈尔滨工程大学水声工程学院,黑龙江哈尔滨150001;哈尔滨工程大学水声技术重点实验室,黑龙江哈尔滨150001;哈尔滨工程大学水声工程学院,黑龙江哈尔滨150001【正文语种】中文【中图分类】TB565.1现代潜艇大量应用减振降噪技术，辐射噪声越来越低，一些安静型潜艇的辐射噪声甚至接近于海洋环境噪声，传统的利用被动声呐探潜的手段受到了很大挑战。
