Applied Acoustics最新文献_第7页

Analysis of performance and aerodynamic noise of centrifugal compressor using non-uniform tip clearance at near-stall condition 近失速状态下使用非均匀顶端间隙的离心式压缩机的性能和空气动力噪声分析

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-07 DOI: 10.1016/j.apacoust.2024.110296

Yipeng Cao , Shaoran Du , Xu Zhan , Yao Song , Yang Liu , Chen Liu

As the demand for high-pressure-ratio and high-flow-rate centrifugal compressors increases, aerodynamic noise has become a key factor constraining their development. This paper investigates the effects of tip clearance on compressor performance and aerodynamic noise at near-stall conditions through numerical calculations and experiments. Firstly, the numerical model of the centrifugal compressor with original tip clearance was established. Then, the compressor’s aerodynamic performance and aerodynamic noise were calculated using the high-precision computational fluid dynamics (CFD) approach and the boundary element method (BEM), and the numerical results were validated against experimental data. Finally, the effects of non-uniform tip clearance on compressor performance and aerodynamic noise were analyzed. The results show that reducing the leading and trailing edge tip clearances improves the compressor’s aerodynamic performance compared to uniform tip clearance, and reducing the trailing edge clearance has a greater effect. Under near-stall conditions, increasing or decreasing tip clearances can somewhat reduce aerodynamic noise compared to uniform tip clearance. The aerodynamic noise is less sensitive to non-uniform tip clearance changes when tip clearance is reduced. However, when tip clearance is increased, smaller non-uniform trailing edge clearances significantly reduce aerodynamic noise.

随着对高压比和大流量离心压缩机需求的增加，空气动力噪声已成为制约其发展的一个关键因素。本文通过数值计算和实验，研究了近失速工况下叶尖间隙对压缩机性能和气动噪声的影响。首先，建立了具有原始顶端间隙的离心式压缩机的数值模型。然后，采用高精度计算流体动力学（CFD）方法和边界元法（BEM）计算了压缩机的气动性能和气动噪声，并将数值结果与实验数据进行了验证。最后，分析了非均匀顶端间隙对压缩机性能和气动噪声的影响。结果表明，与均匀的前缘间隙相比，减小前缘和后缘间隙可以改善压缩机的气动性能，而减小后缘间隙的效果更大。在近失速条件下，与均匀的机头间隙相比，增大或减小机头间隙可在一定程度上降低气动噪声。当减小翼尖间隙时，气动噪声对非均匀翼尖间隙变化的敏感性较低。然而，当机头间隙增大时，较小的非均匀后缘间隙会显著降低气动噪声。

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引用次数: 0

A modified noise prediction model based on vehicles’ random probability distribution for signalized and main road priority-controlled intersections 基于信号灯和主干道优先控制交叉口车辆随机概率分布的改进型噪声预测模型

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-05 DOI: 10.1016/j.apacoust.2024.110330

Xin Deng, Zhaolang Wu, Shiyu Wang, Junshan Lin, Haibo Wang

A modified noise prediction model based on vehicles’ random probability distribution is proposed to address the difficulty of noise prediction caused by various traffic characteristics of different types of intersections. Monte Carlo simulation is used to generate specific vehicle locations with the assumption of time headway is Burr distribution, and traffic noise can be calculated based on the energy superposition principle. The model has been validated as the average absolute error for L_eq of 1.4 dB(A) at both signalized and main road priority-controlled intersections. Applications of two types of intersections are presented. Different noise impacts are indicated in the two intersection modes, as the signalized intersection reduces noise value by 2.1 dB compared with a 0.3 dB increase at priority-controlled intersections with speeds varying from 30 to 50 km/h. Higher speeds result in more concentrated noise values across flow ratios at signalized intersections, while the opposite trend is observed at priority-controlled intersections. Flow ratios of two axes, speed, and receiver locations play different roles in the noise effect of two intersection modes.

针对不同类型交叉口的各种交通特性造成的噪声预测困难，提出了一种基于车辆随机概率分布的修正噪声预测模型。利用蒙特卡罗模拟生成具体的车辆位置，假设时间车距为布尔分布，根据能量叠加原理计算交通噪声。经过验证，该模型在信号灯控制和主干道优先控制交叉口的 Leq 平均绝对误差为 1.4 dB(A)。介绍了两类交叉口的应用。两种交叉口模式的噪声影响不同，信号灯控制交叉口的噪声值降低了 2.1 分贝，而优先控制交叉口的噪声值增加了 0.3 分贝，车速从 30 到 50 公里/小时不等。在信号灯控制的交叉路口，车速越高，各流量比的噪声值越集中，而优先控制交叉路口的趋势则相反。双轴流量比、车速和接收器位置对两种交叉口模式的噪声影响起着不同的作用。

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引用次数: 0

Composite delamination damage location based on non-orthogonal air-coupled ultrasonic guided waves and Artifact-Reduction damage index 基于非正交空气耦合超声导波和伪影-还原损伤指数的复合材料分层损伤定位

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-05 DOI: 10.1016/j.apacoust.2024.110326

Jing Sun, Hui Zhang, Xiaobo Rui, Zhoumo Zeng, Lixin Xu

This study focuses on the localization of delamination damage in composite materials. Due to the attenuation of the air-coupled ultrasound at the gas–solid coupling interface, the signal-to-noise ratio of the air-coupled ultrasonic signal is low, which results in low accuracy of damage detection. This paper proposes a method to locate delamination damage in composite materials. This method uses non-orthogonal Air-coupled Ultrasonic Guided Waves for B-scan; an artifact-reduction damage index (ARDI) is designed with the proportion of the scan paths containing damage information to the entire scan paths. These two exquisite designs improve detection accuracy. Finally, the probability of damage occurrence is calculated, and the detection of the damage location is achieved, with the positioning error of the damage being less than 1.5%.

本研究的重点是复合材料分层损伤的定位。由于空气耦合超声波在气固耦合界面的衰减，空气耦合超声波信号的信噪比较低，导致损伤检测精度不高。本文提出了一种复合材料分层损伤定位方法。该方法采用非正交空气耦合超声波导波进行 B 扫描，并根据含有损伤信息的扫描路径占整个扫描路径的比例设计了减少伪影损伤指数（ARDI）。这两种精巧的设计提高了检测精度。最后，计算出损伤发生的概率，实现损伤位置检测，损伤定位误差小于 1.5%。

引用次数: 0

Virtual source total focusing method for surface defects using leaky Rayleigh waves 利用泄漏瑞利波的表面缺陷虚拟源全聚焦法

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-05 DOI: 10.1016/j.apacoust.2024.110329

Zhiping Liu , Zelong Li , Duo Lyu , Zhiwu Zhang , Hongwei Hu

Leaky Rayleigh waves are sensitive to surface defects and beneficial for automated detection due to their non-contact characteristics. However, the amplitude of the leaky Rayleigh waves is low due to the attenuation of waveform conversion and acoustic waves propagation, which limits the imaging quality for long-distance detection. This study introduces a novel method combining leaky Rayleigh waves detection with virtual source total focusing method. The virtual source (VS) technology enhances the emission energy of leaky Rayleigh waves. Then, the total focusing method (TFM) is applied to acquire high-accuracy images of defects. To reduce noise and artifacts, a weighting function based on the coherence factor (CF) is developed to weight the TFM superimposed signals, thereby achieving high-quality image reconstruction. Experimental results show that compared with the conventional TFM method, the proposed method can effectively improve the amplitude of imaging signals while reducing system noise and imaging artifacts. The lateral accuracy of defects is improved, with the average lateral error of defect size being 0.178 mm. The signal-to-noise ratio (SNR) of ultrasound images is increased by 27.59 dB, and the array performance index (API) of ultrasound images is decreased by 33.78 %. The proposed method provides a new and effective approach for quantitatively assessing the surface defects of metal components using leaky Rayleigh waves.

泄漏瑞利波对表面缺陷很敏感，由于其非接触特性，有利于自动检测。然而，由于波形转换和声波传播的衰减，泄漏瑞利波的振幅较低，限制了远距离检测的成像质量。本研究介绍了一种将漏雷波探测与虚拟声源全聚焦法相结合的新方法。虚拟声源（VS）技术增强了泄漏雷利波的发射能量。然后，应用全聚焦法（TFM）获取高精度的缺陷图像。为了减少噪声和伪影，开发了一种基于相干因子（CF）的加权函数来对 TFM 叠加信号进行加权，从而实现高质量的图像重建。实验结果表明，与传统的 TFM 方法相比，所提出的方法能有效改善成像信号的振幅，同时降低系统噪声和成像伪影。缺陷的横向精度得到提高，缺陷尺寸的平均横向误差为 0.178 毫米。超声图像的信噪比（SNR）提高了 27.59 dB，超声图像的阵列性能指数（API）降低了 33.78 %。所提出的方法为利用泄漏瑞利波定量评估金属部件表面缺陷提供了一种新的有效方法。

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引用次数: 0

Broadband low-transmission study of ventilation metasurfaces based on Archimedean spirals 基于阿基米德螺旋的通风元面的宽带低传输研究

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-05 DOI: 10.1016/j.apacoust.2024.110335

Taoqi Lu , Zhichun Li , Yu Zhang

The primary objectives of acoustic material design include ensuring indoor ventilation and isolating external noise. This study introduces a ventilation metamaterial surface based on Archimedean spirals (ASVM) and calculates its energy transmission coefficient using simulation and the Transfer Matrix Method (TMM). Experimental validation confirms the accuracy of the proposed model, highlighting ASVM’s potential as an effective ventilation metamaterial surface. Subsequently, ASVM is integrated with Helmholtz resonators (HR) to create two new metasurfaces: HR-ASVM without a neck and N-HR-ASVM with a neck. The former exhibits a power transmission coefficient below 0.2 across the broadband range of 1300 Hz to 2500 Hz, while the latter demonstrates superior sound insulation performance (power transmission coefficient below 0.1) from 639 Hz to 2500 Hz, with complete transmission suppression at 710 Hz. Notably, the thickness of N-HR-ASVM at this frequency is only 1/13 of the wavelength. Simulations of the acoustic pressure field and energy flow analyze the mechanisms responsible for low transmission. Finally, the energy transmission coefficient of N-HR-ASVM is experimentally measured and found to align closely with simulation results. This study provides valuable insights into the research on spiral ventilation metamaterial surfaces.

声学材料设计的主要目标包括确保室内通风和隔离外部噪音。本研究介绍了一种基于阿基米德螺旋线的通风超材料表面（ASVM），并利用模拟和传递矩阵法（TMM）计算了其能量传输系数。实验验证证实了所提模型的准确性，凸显了 ASVM 作为有效通风超材料表面的潜力。随后，ASVM 与亥姆霍兹谐振器（HR）相结合，创造出两种新的超材料表面：无颈的 HR-ASVM 和有颈的 N-HR-ASVM。前者在 1300 Hz 至 2500 Hz 的宽带范围内功率传输系数低于 0.2，而后者在 639 Hz 至 2500 Hz 范围内具有卓越的隔音性能（功率传输系数低于 0.1），在 710 Hz 时完全抑制了传输。值得注意的是，N-HR-ASVM 在该频率下的厚度仅为波长的 1/13。声压场和能量流模拟分析了造成低传输的机制。最后，通过实验测量了 N-HR-ASVM 的能量传输系数，发现其与模拟结果非常吻合。这项研究为螺旋通风超材料表面的研究提供了宝贵的见解。

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引用次数: 0

Exploring associations between urban soundscape and contextual factors based on a textual data-driven analysis and mapping approach: A case study in Daejeon, Korea 基于文本数据驱动的分析和绘图方法，探索城市声景与环境因素之间的关联：韩国大田案例研究

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-04 DOI: 10.1016/j.apacoust.2024.110319

Geon-Hee Kim, Tae-Hui Kim, Joo-Young Hong

In soundscape research, it is crucial to understand how contextual factors are associated with people’s perception of acoustic environments. This study proposes a Textual Data-driven Context Analysis and Mapping Method (TD-CAMM), aiming at comprehensively exploring the intricate relationship between soundscape and contextual factors. Through a case study employing TD-CAMM, we demonstrate its effectiveness in quantitatively analyzing text-based contextual data, facilitating the identification of patterns and interrelations among diverse contextual elements via statistical analyses. Utilizing collected contextual data including the purpose of visit, time of use, sound source, emotion, and perceived affective quality, we conducted a hierarchical cluster analysis to characterize soundscapes of the selected locations, revealing four distinct clusters. Subsequently, association rule analysis was performed to identify unique associations among contextual elements shaping the soundscapes within each cluster. Cluster 1, the 'Nightlife Zone of Noisy Urban Settings' was characterized by 'Restless' and 'Noisy' emotions associated with nighttime activities. Cluster 2, the 'Lively Human-Centered Zone for Day and Evening Activities' reflected vibrant human interactions. Cluster 3, identified as 'Restless and Noisy Urban Traffic' was marked by transportation sounds, emphasizing urban bustle. Lastly, Cluster 4, the 'Tranquil Urban Nature Walk' encompassed serene natural spaces with 'Tranquil' emotions amidst natural sounds. These findings present a comprehensive approach to evaluating urban soundscapes, with potential applications in future urban soundscape research and design.

在声景研究中，了解语境因素如何与人们对声环境的感知相关联至关重要。本研究提出了一种文本数据驱动的语境分析和绘图方法（TD-CAMM），旨在全面探索声景与语境因素之间错综复杂的关系。通过采用 TD-CAMM 的案例研究，我们展示了该方法在定量分析基于文本的语境数据方面的有效性，有助于通过统计分析识别不同语境元素之间的模式和相互关系。利用收集到的上下文数据（包括访问目的、使用时间、声音来源、情感和感知情感质量），我们对所选地点的声音景观进行了分层聚类分析，发现了四个不同的聚类。随后，我们进行了关联规则分析，以确定每个聚类中形成声景的环境因素之间的独特关联。群组 1 "嘈杂城市环境中的夜生活区 "的特点是与夜间活动相关的 "烦躁 "和 "嘈杂 "情绪。第 2 组 "以人为本的昼夜活动区 "反映了充满活力的人际交往。第 3 组是 "躁动喧闹的城市交通"，以交通声音为特征，强调城市的喧嚣。最后，第 4 组 "宁静的城市自然漫步 "包含了宁静的自然空间，在自然的声音中蕴含着 "宁静 "的情感。这些研究结果为评估城市声景提供了一种全面的方法，在未来的城市声景研究和设计中具有潜在的应用价值。

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引用次数: 0

ISO test track influence on the EU tyre label noise value ISO 测试轨道对欧盟轮胎标签噪音值的影响

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-04 DOI: 10.1016/j.apacoust.2024.110315

Truls Berge , Piotr Mioduszewski , Maciej Hałucha , Janusz Bohatkiewicz

In 2009, the European Union (EU) introduced a directive governing the labelling of tyres, which underwent revision in 2020. This labelling system encompasses three key parameters related to tyre performance: wet grip (safety), rolling resistance (energy consumption), and external rolling noise (environmental impact). These label values serve as crucial information for customers seeking to purchase replacement tyres for their vehicles.

However, the accuracy and reliability of noise measurements have been a concern. Testing conducted across various ISO-standardized tracks has revealed significant inconsistencies in noise levels, with variations of 4–5 dB between tracks. Such discrepancies directly impact the labelling process, introducing uncertainty.

This paper presents results of tyre noise measurements conducted on a limited number of ISO test tracks and proposes a methodology to mitigate track-to-track variability. The study exclusively focuses on passenger car tyres. By addressing these inconsistencies, this research aims to enhance the accuracy and reliability of tyre noise labelling, thereby facilitating informed consumer decision-making and promoting environmental sustainability.

2009 年，欧盟（EU）出台了一项关于轮胎标签的指令，并于 2020 年进行了修订。该标签系统包括与轮胎性能有关的三个关键参数：湿地抓地力（安全）、滚动阻力（能耗）和外部滚动噪音（环境影响）。这些标签值是客户为其车辆购买替换轮胎的关键信息。然而，噪声测量的准确性和可靠性一直是个问题。然而，噪声测量的准确性和可靠性一直是个问题。在各种 ISO 标准轨道上进行的测试表明，噪声水平存在明显的不一致性，轨道之间的差异可达 4-5 分贝。本文介绍了在数量有限的 ISO 测试轨道上进行的轮胎噪声测量结果，并提出了一种方法来减少轨道间的差异。该研究专门针对乘用车轮胎。通过解决这些不一致性，本研究旨在提高轮胎噪声标签的准确性和可靠性，从而帮助消费者做出明智的决策，促进环境的可持续发展。

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引用次数: 0

Validation of an eigenvalue-based inverse method for estimating locally-reacting surface impedance 基于特征值的反演法对局部反应表面阻抗估算的验证

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-04 DOI: 10.1016/j.apacoust.2024.110332

Albert G. Prinn , Pablo Panter , Andreas Walther , Emanuël A.P. Habets

Accurate boundary condition descriptions are essential for creating accurate computational models for room acoustics. These descriptions are often defined in terms of absorption coefficients or surface impedances. However, obtaining complex-valued, frequency-dependent values for an acoustically absorbing material sample at low frequencies is a challenging task. In fact, the current measurement standard ISO 354:2003 does not provide a method for measuring absorption coefficients below 100 Hz. In this paper, a recently proposed eigenvalue-based inverse method for estimating locally-reacting impedance at measurement system resonance frequencies is validated. The validation uses data from three samples measured in an impedance tube. The method is also used to estimate complex-valued, frequency-dependent impedances at frequencies below 100 Hz in a measured reverberant room and in a simulated reverberation chamber.

准确的边界条件描述对于创建精确的室内声学计算模型至关重要。这些描述通常用吸声系数或表面阻抗来定义。然而，获取低频吸声材料样本的复值、频率相关值是一项极具挑战性的任务。事实上，目前的测量标准 ISO 354:2003 并没有提供测量 100 赫兹以下吸声系数的方法。本文验证了最近提出的一种基于特征值的逆方法，用于估算测量系统共振频率下的局部反应阻抗。验证使用了在阻抗管中测量的三个样品的数据。该方法还用于估算在测量混响室和模拟混响室中频率低于 100 Hz 的复值频率相关阻抗。

引用次数: 0

A case study of railway curve squeal radiated from both the outer and inner wheel 从外轮和内轮辐射的铁路曲线尖叫案例研究

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-03 DOI: 10.1016/j.apacoust.2024.110327

P.T. Torstensson , A. Pieringer , M. Höjer , R. Nilsson , V. Simonsson

This case study is presented after observations were made that partially contrast the prevailing picture of railway curve squeal given in the literature. These are observations with significance both for modelling and condition monitoring. The current case study will be followed by a subsequent investigation focused on the validation and application of a simulation model to investigate root-causes for curve squeal at the Stockholm metro. Curve squeal in a 213 m radius curve on the Stockholm metro is studied. Data includes track characteristics (rail profile, rail roughness and gauge width) and noise measured at the trackside as well as by two vehicles equipped with an on-board mounted noise monitoring system. The current case study contrasts field measurements of curve squeal reported in the literature by a relative shift of emitted noise towards higher frequencies. Wayside noise measurements in the studied curve during a few hours showed squeal generation for all vehicle passages with dominating 1/3 octave band centre frequencies in the range between 6.3–15.8 kHz. Noise data measured during one year of regular traffic of two vehicles equipped with a monitoring system were obtained. The occurrence of curve squeal was analysed through an implementation of the curve squeal detection algorithm in operation at the Stockholm metro. This algorithm was also applied to search for events of squeal noise radiation from the outer wheel. Results show emissions of squeal noise from the inner and outer wheel for 65 % and 8 % of the vehicle passages through the studied curve, respectively. Further, the occurrence of curve squeal radiated from the inner wheel was found to increase by 10 % after rail grinding. In the literature, squeal radiated from the outer wheel is described as having an intermittent character with magnified spectral components in the frequency range between 5–10 kHz. In contrast, the current work presents sustained tonal squeal generated from the outer wheel with similar noise characteristics as typically related to ordinary curve squeal.

本案例研究是在对文献中铁路曲线尖叫的普遍情况进行部分对比观察后提出的。这些观察结果对建模和状态监测都具有重要意义。本案例研究之后还将进行后续调查，重点是验证和应用仿真模型来研究斯德哥尔摩地铁曲线尖叫的根本原因。研究对象为斯德哥尔摩地铁中半径 213 米的曲线上出现的曲线尖叫。数据包括轨道特征（轨道轮廓、轨道粗糙度和轨距宽度）和在轨道旁测量到的噪音，以及由两辆配备了车载噪音监测系统的车辆测量到的噪音。目前的案例研究与文献中报道的曲线尖叫的实地测量结果形成对比，发出的噪声相对转向更高的频率。几个小时内对所研究曲线的路边噪声测量结果显示，所有车辆通过时都会产生尖叫声，1/3 倍频带中心频率主要在 6.3-15.8 kHz 之间。此外，还获得了两辆装有监测系统的车辆在一年的正常行车期间测得的噪声数据。通过实施斯德哥尔摩地铁运行的曲线尖叫检测算法，对曲线尖叫的发生进行了分析。该算法还用于搜索外轮发出的尖叫声。结果显示，在所研究的弯道中，分别有 65% 和 8% 的车辆通过时从内轮和外轮发出尖叫声。此外，内侧车轮辐射的曲线尖叫发生率在钢轨打磨后增加了 10%。在文献中，外侧车轮辐射的尖叫声被描述为具有间歇性，在 5-10 kHz 的频率范围内具有放大的频谱成分。与此相反，目前的工作显示了从外轮产生的持续的音调尖叫声，其噪声特征与通常的普通曲线尖叫声相似。

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引用次数: 0

Ultra-thin arc-shaped conformal metasurface coating for broadband noise reduction in underwater pipeline 用于水下管道宽带降噪的超薄弧形保形超表面涂层

IF 3.4 2区物理与天体物理 Q1 ACOUSTICS

Applied Acoustics

Pub Date : 2024-10-03 DOI: 10.1016/j.apacoust.2024.110314

Yuze Liu , Guangming Cao , Chongrui Liu , Fuyin Ma

In this paper, a design method of arc-shaped conformal metasurface underwater muffling coating for noise reduction of fluid-filled pipeline is proposed. Combining Fabry-Pèrot(FP) channel and Helmholtz resonant cavity structure, a thin-layer metasurface of fan-shaped ultra-thin labyrinth channel is designed, which is conformally laid on the inner wall of the circular pipeline, and underwater low-frequency broadband noise reduction is realized by sound absorption. With the advantage of relatively loose size constraint in the length direction of the pipeline, we transfer the thickness dimension required for low-frequency broadband sound absorption to the length direction, which greatly reduces the thickness of the coating. Because the elasticity of solid structure is close to the compressibility of water medium, the coupling strength between structure and underwater sound wave is enhanced, and the loss ability of thin-layer structure to low-frequency sound wave is improved, which overcomes the contradiction between thin-layer structure and middle-low frequency noise reduction. By overlaying and combining structures with excellent performance in different noise reduction frequency bands in the axial direction and designing high-order sound absorption units, broadband muffling performance is achieved, and micro-perforated structures are used instead of macro-perforated structures to avoid the possibility that sand and gravel enter the structure and lead to the failure of sound absorption performance. The metasurface broadband muffling coating designed in this paper has a small thickness, which can shield the noise propagation while ensuring that the pipe can flow through the fluid, and solve the problem of the acoustic short circuit of the underwater pipeline, which is of great significance to the noise reduction of the underwater pipeline.

本文提出了一种用于充液管道降噪的弧形共形元表面水下消声涂层的设计方法。结合法布里-裴罗（Fabry-Pèrot，FP）通道和亥姆霍兹谐振腔结构，设计了扇形超薄迷宫通道的薄层元表面，将其保形铺设在圆形管道内壁上，通过吸声实现水下低频宽带降噪。利用管道长度方向尺寸约束相对宽松的优势，将低频宽带吸声所需的厚度尺寸转移到长度方向，大大减小了涂层厚度。由于固体结构的弹性接近水介质的可压缩性，增强了结构与水下声波的耦合强度，提高了薄层结构对低频声波的损耗能力，克服了薄层结构与中低频降噪之间的矛盾。通过将轴向不同降噪频段性能优异的结构叠加组合，设计高阶吸声单元，实现宽带消声性能，并采用微穿孔结构代替大穿孔结构，避免砂石进入结构导致吸声性能失效的可能性。本文设计的元面宽带消声涂层厚度较小，在保证管道流体流动的同时可以屏蔽噪声传播，解决了水下管道声学短路问题，对水下管道降噪具有重要意义。

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引用次数: 0