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Control Strategies and Mechanisms for Active Control of sound transmission into a Vibro-acoustic Enclosure

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Journal of Marine Science and Application 2011年第2期10卷 206-214页

作者：靳国永冯娜杨铁军 College of Power and Energy Engineering Harbin Engineering University

An analytical study was presented on active control of sound transmission into a vibro-acoustic enclosure comprising two flexible plates. Two types of actuators were used, i.e. acoustic actuator and distributed lead zirconate titanate piezoelectric (PZT) actuator instead of point force actuator. Using the modal acoustic transfer impedance-mobility matrices, the excitation and interaction in the coupled sound transmission system can be described with clear physical significance. With the control system designed to globally reduce the sound field, different control system configurations were considered, including the structural actuator on the incident plate, actuator on the receiving plate, acoustic actuator on the cavity, and their combinations. The effectiveness and performance of the control strategy corresponding to each system configuration were compared and discussed. The role and control mechanism of each type of actuator were of particular interest. It was shown that the incident plate actuator is effective in controlling the cavity-dominated modes and the structural modes dominated by the incident plate and receiving plate. Two main control mechanisms are involved in this control configuration, i.e., modal suppressing and modal rearrangement. For control system configuration with only acoustic actuator in the enclosure, the mechanism involved in this arrangement is purely modal suppression. Desirable placements of structural actuators in terms of total potential energy reduction were also discussed.

关键词： sound transmission active control control mechanism enclosure piezoelectric (PZT) actuators

Numerical Investigation of transmission of Low Frequency sound Through a Smooth Air-water Interface

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Journal of Marine Science and Application 2015年第3期14卷 334-342页

作者： Parviz Ghadimi Ahreza Bolghasi Mohammad A. Feizi Chekab Rahim Zamanian Department of Marine Technology Amirkabir University of Technology Tehran 15875-4413 Iran International Campus-Mechanical Engineering Group Amirkabir University of Technology Tehran 15875-4413 Iran

It is the traditional belief that sound transmission from water to the air is very weak due to a large contrast between air and water impedances. Recently, the enhanced sound transmission and anomalous transparency of air-water interface have been introduced. Anomalous transparency of air-water interface states that the sound generated by a submerged shallow depth monopole point source localized at depths less than 1/10 sound wavelength, can be transmitted into the air with omni-directional pattern. The generated sound has 35 times higher power compared to the classical ray theory prediction. In this paper, sound transmission through air-water interface for a localized underwater shallow depth source is examined. To accomplish this, two-phase coupled Helmholtz wave equations in two-phase media of air-water are solved by the commercial finite element based COMSOL Multiphysics software. Ratios of pressure amplitudes of different sound sources in two different underwater and air coordinates are computed and analyzed against non-dimensional ratio of the source depth （D） to the sound wavelength （λ）. The obtained results are compared with the experimental data and good agreement is displayed.

关键词： enhanced sound transmission anomalous transparency air-water interface shallow depth source sound transmission Helmholtz wave equations

transmission OF sound ENERGY THROUGH ORTHOGONALLY RIB-STIFFENED DOUBLE-LEAF STRUCTURES

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TRANSMISSION OF SOUND ENERGY THROUGH ORTHOGONALLY RIB-STIFFE...

Numerical analysis of ossicular chain lesion of human ear

The Third International Conference on Dynamics, Vibration and Control

作者： F.X.Xin~* and T.J.Lu MOE Key Laboratory for Strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an 710049 P.R.China

＜正＞The vibration and sound transmission characteristics of periodically rib-stiffened double-leaf structures is of growing interest due to their wide range applications in civil and transport engineering（e.g.,as the cabin skin of aircrafts,marine ships and express trains）.At low frequencies,a rib-stiffened structure can be approximated as an orthotropic panel when the wavelength of the flexural wave in the panel is much greater than the separation distance of the *** high frequencies,however,when the wavelength is comparable with the stiffener separation,the spatial periodicity of the structure should be carefully taken account of in the theoretical analysis.

关键词： sound transmission double-leaf partition orthogonal rib-stiffener vibroacoustic performance

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Acta Mechanica Sinica 2009年第2期25卷 241-247页

作者： Yingxi Liu Sheng Li Xiuzhen Sun State Key Laboratory of Structural Analysis for IndustrialEquipment Dalian University of Technology116024 Dalian China ENT Department The Second Affiliated Hospital of DalianMedical University 116025 Dalian China

Abstract Lesion of ossicular chain is a common ear disease impairing the sense of hearing. A comprehensive numerical model of human ear can provide better understanding of sound transmission. In this study, we propose a three-dimensional finite element model of human ear that incorporates the canal, tympanic membrane, ossicular bones, middle ear suspensory ligaments/muscles, middle ear cavity and inner ear fluid. Numerical analysis is conducted and employed to predict the effects of middle ear cavity, malleus handle defect, hypoplasia of the long process of incus, and stapedial crus defect on sound transmission. The present finite element model is shown to be reasonable in predicting the ossicular mechanics of human ear.

关键词： Finite element model Ossicular chain lesionAcoustic-structural coupled analysis Middle ear cavity sound transmission

CABIN NOISE SOURCE-PATH IDENTIFICATIONFOR AD-200 ULTRALIGHT AIRCRAFT

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Chinese Journal of Aeronautics 1995年第1期8卷 69-73页

作者： Yin Jianping Hu Zhangwei Zhang Qiang(Department of Aerodynamics, Nanjing University of Aeronauticsand Astronautics, Nanjing, China, 210016)

ＣＡＢＩＮＮＯＩＳＥＳＯＵＲＣＥ－ＰＡＴＨＩＤＥＮＴＩＦＩＣＡＴＩＯＮＦＯＲＡＤ－２００ＵＬＴＲＡＬＩＧＨＴＡＩＲＣＲＡＦＴＹｉｎＪｉａｎｐｉｎｇ；ＨｕＺｈａｎｇｗｅｉ；ＺｈａｎｇＱｉａｎｇ（Ｄｅｐａｒｔｍｅｎｔｏｆ... 详细信息

ＣＡＢＩＮＮＯＩＳＥＳＯＵＲＣＥ－ＰＡＴＨＩＤＥＮＴＩＦＩＣＡＴＩＯＮＦＯＲＡＤ－２００ＵＬＴＲＡＬＩＧＨＴＡＩＲＣＲＡＦＴＹｉｎＪｉａｎｐｉｎｇ；ＨｕＺｈａｎｇｗｅｉ；ＺｈａｎｇＱｉａｎｇ（ＤｅｐａｒｔｍｅｎｔｏｆＡｅｒｏｄｙｎａｍｉｃｓ，Ｎａｎｊ...

关键词： sound transmission noise measurement sources ultralight aircraft

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琉球群岛附近海域声场分析

琉球群岛附近海域声场分析

作者：代民果浙江大学

学位级别：硕士

水体中各种能量辐射形式中，光波和电磁波的衰减都非常大，传播距离较短，而以声波的传播性能为最好。目前水声技术已是开发海洋和研究海洋广泛采用和行之有效的手段，如水下通讯、声遥测遥控、数据图像传播，以及用声波遥测海洋涡漩的... 详细信息

水体中各种能量辐射形式中，光波和电磁波的衰减都非常大，传播距离较短，而以声波的传播性能为最好。目前水声技术已是开发海洋和研究海洋广泛采用和行之有效的手段，如水下通讯、声遥测遥控、数据图像传播，以及用声波遥测海洋涡漩的运动和变化与全球海洋温度的监测等方面。而这些技术要求进一步研究声波传播规律与海洋环境的定量关系。论文主要作了以下工作。通过数据处理，得出了琉球群岛附近海域声速最小值和及其出现深度的分布规律，研究了横跨和穿越宫古水道两个断面上声场上述特征的变化，探讨了温度分布和声速最小值的分布的关系;研究了单频声源所发出声波在深海的能量传播途径和传播损失，得出不同频率和不同深度对于声传播损失的影响。结果表明在陆架海域声速最小值分布主要受海水表面温度和底层温度控制，其控制范围随季节变化，春、秋季声速最小值分布几乎完全受海水底层温度分布控制;在深海海域，声速最小值分布及其出现深度相对稳定;单频声源声传播损失与声源的垂向位置和频率有关，频率和深度变化对声传播损失影响很大;表层10Hz以上的声波难以在表层传播，且传播损失大。论文的主要创新之处是用数据库资料对琉球群岛附近海域声速最小值及其出现深度作了大面积预估，避免了实测CTD资料站位少、水平分辨率低、易受气候等偶然性影响的不足之处;采用声速最小值分布来分析这一海域的声学性质，而没有采用传统的声速平面分布。并指出东海陆架浅海声速最小值分布主要与海水表面温度和底层温度分布有关;用穿越和横跨宫古水道的两个声速断面揭示陆坡上升流，并以此解释冲绳岛外侧声速最小值和声速最小值深度四季的剧烈变化;同时讨论单频声源声线传播和频率、深度对声传播损失的影响。

关键词： Ryukyu minimal sounding speed value depth corresponding to minimal sound speed value deep-water-sound channel sound transmission transmission loss