Pub Date : 2025-03-19DOI: 10.1016/j.apacoust.2025.110669
Zi Yang , Erzheng Fang
The concept of polarization originated in optics and has been extensively developed and applied in fields such as electromagnetism and seismicity. With the advent of vector sensors, this concept has been introduced into acoustics. However, research on acoustic polarization phenomena in underwater acoustics remains relatively scarce. Therefore, it is necessary to conduct an in-depth investigation into polarization phenomena in acoustic fields. This study proposes a method to analyze and verify the polarization phenomenon in underwater acoustic vector fields. Firstly, the article establishes the basic model of polarization phenomenon in an acoustic vector field, illustrates the time evolution of a bivariate signal in a three-dimensional representation, and elucidates the physical significance underlying this phenomenon. Subsequently, the polarization ellipse in the acoustic vector field and its characterization parameters are derived theoretically and estimated by simulation images. On this basis, the theory is extended to three-dimensional space, and a visual representation of signal polarization characteristics is achieved through the concept of polarization degree. Finally, the proposed method is validated by external field experiments and data analysis. The experimental results are consistent with the theoretical expectations, demonstrating the existence of polarization phenomena in the acoustic vector field.
{"title":"Analysis and validation method for polarization phenomena based on acoustic vector Hydrophones","authors":"Zi Yang , Erzheng Fang","doi":"10.1016/j.apacoust.2025.110669","DOIUrl":"10.1016/j.apacoust.2025.110669","url":null,"abstract":"<div><div>The concept of polarization originated in optics and has been extensively developed and applied in fields such as electromagnetism and seismicity. With the advent of vector sensors, this concept has been introduced into acoustics. However, research on acoustic polarization phenomena in underwater acoustics remains relatively scarce. Therefore, it is necessary to conduct an in-depth investigation into polarization phenomena in acoustic fields. This study proposes a method to analyze and verify the polarization phenomenon in underwater acoustic vector fields. Firstly, the article establishes the basic model of polarization phenomenon in an acoustic vector field, illustrates the time evolution of a bivariate signal in a three-dimensional representation, and elucidates the physical significance underlying this phenomenon. Subsequently, the polarization ellipse in the acoustic vector field and its characterization parameters are derived theoretically and estimated by simulation images. On this basis, the theory is extended to three-dimensional space, and a visual representation of signal polarization characteristics is achieved through the concept of polarization degree. Finally, the proposed method is validated by external field experiments and data analysis. The experimental results are consistent with the theoretical expectations, demonstrating the existence of polarization phenomena in the acoustic vector field.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110669"},"PeriodicalIF":3.4,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-18DOI: 10.1016/j.apacoust.2025.110684
Weifan Kong , Tao Fu , Tao Liu , Jinxiang Fang , Sen Wang , Chao Yang , Miao Zhao
The increase of the running speed of high-speed trains is accompanied by the continuous increase of the internal noise of the carriage, and the total noise reduction capacity of the sandwich structure, which is the main component of the carriage wall, is limited under the constraints of space dimension and size, which poses a new challenge to the acoustic performance design of the sandwich structure. Based on that, this paper proposes a novel compact composite structure, which consists of a flower-shaped Helmholtz resonator incorporating an embedded tube, a microperforated plate, and a spiral-shaped labyrinth sound-absorbing structure from top to bottom. Simulations of the structure were performed utilizing the finite element analysis software COMSOL, and the results were verified through standing wave tube sound absorption tests. A strong alignment was noted between the experimental outcomes and the simulation results. The results reveal that the average sound absorption coefficient of the structure surpasses 0.95 within the frequency band of 394 Hz to 548 Hz, achieving nearly perfect sound wave absorption. At the resonance frequency of 394 Hz, the peak absorption coefficient attains 0.981369, despite the structure’s thickness being only one-fifteenth of the wavelength corresponding to the absorption peak frequency, highlighting its distinctive deep-subwavelength properties. Even when the structure’s height is reduced to 60 mm, it maintains a wide sound absorption bandwidth, featuring a bandwidth ratio of 70 % where the sound absorption coefficient exceeds 0.5. The structure exemplifies deep-subwavelength properties by effectively managing large wavelengths despite its small size. Furthermore, the energy absorption characteristics of the composite structure are analyzed. It is found that the composite structure has excellent energy absorption characteristics and sound absorption performance. This study proposes a lightweight metastructure with exceptional acoustic performance, it has potential application value in the skin structure of high-speed trains and other transportation equipment.
{"title":"Multifunctional hybrid metastructure with a combination of flower-shaped Helmholtz resonator and spiral labyrinth: Synergy enhancement in broadband sound absorption and high energy absorption performance","authors":"Weifan Kong , Tao Fu , Tao Liu , Jinxiang Fang , Sen Wang , Chao Yang , Miao Zhao","doi":"10.1016/j.apacoust.2025.110684","DOIUrl":"10.1016/j.apacoust.2025.110684","url":null,"abstract":"<div><div>The increase of the running speed of high-speed trains is accompanied by the continuous increase of the internal noise of the carriage, and the total noise reduction capacity of the sandwich structure, which is the main component of the carriage wall, is limited under the constraints of space dimension and size, which poses a new challenge to the acoustic performance design of the sandwich structure. Based on that, this paper proposes a novel compact composite structure, which consists of a flower-shaped Helmholtz resonator incorporating an embedded tube, a microperforated plate, and a spiral-shaped labyrinth sound-absorbing structure from top to bottom. Simulations of the structure were performed utilizing the finite element analysis software COMSOL, and the results were verified through standing wave tube sound absorption tests. A strong alignment was noted between the experimental outcomes and the simulation results. The results reveal that the average sound absorption coefficient of the structure surpasses 0.95 within the frequency band of 394 Hz to 548 Hz, achieving nearly perfect sound wave absorption. At the resonance frequency of 394 Hz, the peak absorption coefficient attains 0.981369, despite the structure’s thickness being only one-fifteenth of the wavelength corresponding to the absorption peak frequency, highlighting its distinctive deep-subwavelength properties. Even when the structure’s height is reduced to 60 mm, it maintains a wide sound absorption bandwidth, featuring a bandwidth ratio of 70 % where the sound absorption coefficient exceeds 0.5. The structure exemplifies deep-subwavelength properties by effectively managing large wavelengths despite its small size. Furthermore, the energy absorption characteristics of the composite structure are analyzed. It is found that the composite structure has excellent energy absorption characteristics and sound absorption performance. This study proposes a lightweight metastructure with exceptional acoustic performance, it has potential application value in the skin structure of high-speed trains and other transportation equipment.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110684"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-18DOI: 10.1016/j.apacoust.2025.110678
Shancheng Tao , Liu Liu , Zhaoyu Li , Lihua Tang , Zhibin Yu , Geng Chen
Recent studies have reported on the various nonlinear behaviors (e.g., synchronization) resulting from the mutual interaction between a thermoacoustic oscillator and an external acoustic driver producing sinusoidal waves. This work extends previous research by experimentally investigating the dynamic behavior of a thermoacoustic oscillator subjected to external disturbances with different waveforms including triangular and irregular waves. The experimental data are analyzed using various signal processing techniques such as Fast Fourier Transform, wavelet transform, and phase space trajectories. Results reveal that apart from sinusoidal waves, both triangular and irregular waves can be utilized to synchronize the thermoacoustic oscillator. When synchronization occurs, the oscillator will transit from initial periodic oscillations at the natural frequency to final periodic oscillations at the driving frequency. The acoustic pressure resembles the external disturbance at the open end (e.g., triangular waves) but shifts towards sinusoidal waves when approaching the closed end. It is found that synchronization can happen if the dominant frequency of the external disturbance closely aligns with the natural frequency of the oscillator, even in the presence of harmonic components. This study provides an experimental framework for investigating the dynamic behavior of thermoacoustic oscillators under external disturbances, enhancing our understanding of synchronization phenomena in thermoacoustic devices.
{"title":"Experimental Investigations on the Interplay between a thermoacoustic oscillator and an external acoustic driver with different waveforms","authors":"Shancheng Tao , Liu Liu , Zhaoyu Li , Lihua Tang , Zhibin Yu , Geng Chen","doi":"10.1016/j.apacoust.2025.110678","DOIUrl":"10.1016/j.apacoust.2025.110678","url":null,"abstract":"<div><div>Recent studies have reported on the various nonlinear behaviors (e.g., synchronization) resulting from the mutual interaction between a thermoacoustic oscillator and an external acoustic driver producing sinusoidal waves. This work extends previous research by experimentally investigating the dynamic behavior of a thermoacoustic oscillator subjected to external disturbances with different waveforms including triangular and irregular waves. The experimental data are analyzed using various signal processing techniques such as Fast Fourier Transform, wavelet transform, and phase space trajectories. Results reveal that apart from sinusoidal waves, both triangular and irregular waves can be utilized to synchronize the thermoacoustic oscillator. When synchronization occurs, the oscillator will transit from initial periodic oscillations at the natural frequency to final periodic oscillations at the driving frequency. The acoustic pressure resembles the external disturbance at the open end (e.g., triangular waves) but shifts towards sinusoidal waves when approaching the closed end. It is found that synchronization can happen if the dominant frequency of the external disturbance closely aligns with the natural frequency of the oscillator, even in the presence of harmonic components. This study provides an experimental framework for investigating the dynamic behavior of thermoacoustic oscillators under external disturbances, enhancing our understanding of synchronization phenomena in thermoacoustic devices.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110678"},"PeriodicalIF":3.4,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643509","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.apacoust.2025.110673
Zhiwen Qiao , Songzuo Liu , Dexu Wang , Yipeng Xing , Tianyi Liu , Jiaxuan Li
Bio-inspired underwater acoustic communication has emerged as a promising approach for secure underwater communication by camouflaging signals as marine mammal vocalizations. However, conventional bio-inspired communication methods predominantly rely on fixed cetacean whistle patterns or limited whistle databases. The inherent predictability in signal frame structures significantly boosts their vulnerability to pattern recognition and adversarial detection. This consequently weakens the fundamental premise of bio-inspired communication systems, namely, their capacity to emulate natural marine mammal vocalizations for covert operations. To address this limitation, our research group proposed a novel bio-inspired secure communication model utilizing a piecewise cubic hermite interpolating polynomial (PCHIP) for simple whistle generation. The proposed approach ensured frequency continuity in signal design while maintaining high similarity to natural cetacean whistles. Subsequently, an improved chirp spread spectrum (CSS) modulation scheme was developed, and a PCHIP-based spread spectrum algorithm was introduced to generate random time-frequency spectral profiles. Particularly, randomly generated synchronization headers were incorporated with sliding correlation in the proposed system, enabling individual whistles to achieve both synchronization and information transmission capabilities. The integrated method significantly reinforced the covertness of bio-inspired communication while maintaining communication efficiency. The simulation results in shallow water environments demonstrated the effectiveness of our approach. Meanwhile, sea trials successfully achieved communication over 10 km distances with a bit error rate of , validating the practical viability of the proposed system.
{"title":"Bio-inspired underwater acoustic communication through PCHIP-based whistle generation and improved CSS modulation","authors":"Zhiwen Qiao , Songzuo Liu , Dexu Wang , Yipeng Xing , Tianyi Liu , Jiaxuan Li","doi":"10.1016/j.apacoust.2025.110673","DOIUrl":"10.1016/j.apacoust.2025.110673","url":null,"abstract":"<div><div>Bio-inspired underwater acoustic communication has emerged as a promising approach for secure underwater communication by camouflaging signals as marine mammal vocalizations. However, conventional bio-inspired communication methods predominantly rely on fixed cetacean whistle patterns or limited whistle databases. The inherent predictability in signal frame structures significantly boosts their vulnerability to pattern recognition and adversarial detection. This consequently weakens the fundamental premise of bio-inspired communication systems, namely, their capacity to emulate natural marine mammal vocalizations for covert operations. To address this limitation, our research group proposed a novel bio-inspired secure communication model utilizing a piecewise cubic hermite interpolating polynomial (PCHIP) for simple whistle generation. The proposed approach ensured frequency continuity in signal design while maintaining high similarity to natural cetacean whistles. Subsequently, an improved chirp spread spectrum (CSS) modulation scheme was developed, and a PCHIP-based spread spectrum algorithm was introduced to generate random time-frequency spectral profiles. Particularly, randomly generated synchronization headers were incorporated with sliding correlation in the proposed system, enabling individual whistles to achieve both synchronization and information transmission capabilities. The integrated method significantly reinforced the covertness of bio-inspired communication while maintaining communication efficiency. The simulation results in shallow water environments demonstrated the effectiveness of our approach. Meanwhile, sea trials successfully achieved communication over 10 km distances with a bit error rate of <span><math><msup><mrow><mn>10</mn></mrow><mrow><mo>−</mo><mn>4</mn></mrow></msup></math></span>, validating the practical viability of the proposed system.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110673"},"PeriodicalIF":3.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-17DOI: 10.1016/j.apacoust.2025.110672
Yibo Huang , Chong Li , Zhiyong Li , Qiuyu Zhang
The computational accuracy and parameter spacing of the existing chaos result in the gradual degradation of the chaos, which makes the sequence become periodic sequence, and the divergence rate and divergence index of the existing chaos are low. In addition, the current speech encryption algorithm has high complexity and low computational efficiency. To solve these problems, a three-dimensional quadratic exponential chaos is proposed and an efficient speech encryption algorithm is designed. To solve the problem of slow numerical divergence, the double exponential nesting structure is used and the expansion factor is introduced to effectively reduce the number of iterations when complete chaos is reached. In order to improve the internal complexity of chaotic sequence, the whole chaotic equation is standardized, so that the generated chaotic sequence has a wide distribution. Considering that the algorithm can be stably deployed in the hardware chip in the future, and take into account the encryption rate. In this paper, the speech encryption algorithm adopts the parallel processing of confusion and diffusion, and makes the residual processing of the generated encrypted speech to improve the scrambling effect and encryption efficiency. Simulation results show that the proposed chaos equation achieves remarkable exponential divergence rate, robustness and hardware deployability. The proposed speech encryption algorithm has high efficiency, low complexity, high noise ratio, can resist a series of attacks, and has high security. This paper presents an efficient encryption strategy for speech encryption.
{"title":"Efficient speech encryption algorithm based on three-dimensional quadratic exponential robust chaos","authors":"Yibo Huang , Chong Li , Zhiyong Li , Qiuyu Zhang","doi":"10.1016/j.apacoust.2025.110672","DOIUrl":"10.1016/j.apacoust.2025.110672","url":null,"abstract":"<div><div>The computational accuracy and parameter spacing of the existing chaos result in the gradual degradation of the chaos, which makes the sequence become periodic sequence, and the divergence rate and divergence index of the existing chaos are low. In addition, the current speech encryption algorithm has high complexity and low computational efficiency. To solve these problems, a three-dimensional quadratic exponential chaos is proposed and an efficient speech encryption algorithm is designed. To solve the problem of slow numerical divergence, the double exponential nesting structure is used and the expansion factor <span><math><mi>b</mi><mi>e</mi><mi>t</mi><mi>a</mi></math></span> is introduced to effectively reduce the number of iterations when complete chaos is reached. In order to improve the internal complexity of chaotic sequence, the whole chaotic equation is standardized, so that the generated chaotic sequence has a wide distribution. Considering that the algorithm can be stably deployed in the hardware chip in the future, and take into account the encryption rate. In this paper, the speech encryption algorithm adopts the parallel processing of confusion and diffusion, and makes the residual processing of the generated encrypted speech to improve the scrambling effect and encryption efficiency. Simulation results show that the proposed chaos equation achieves remarkable exponential divergence rate, robustness and hardware deployability. The proposed speech encryption algorithm has high efficiency, low complexity, high noise ratio, can resist a series of attacks, and has high security. This paper presents an efficient encryption strategy for speech encryption.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110672"},"PeriodicalIF":3.4,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-14DOI: 10.1016/j.apacoust.2025.110628
Raffaele Dragonetti , Elio Di Giulio , Annunziata Bruno , Antonio Scofano , Rosario Aniello Romano
In this paper the reflected sound field over micro-perforated systems (MPPS) is investigated by using experimental, numerical and theoretical approaches. Two types of MPPS configurations are considered: one with an air cavity termination and the other with a honeycomb layer termination. A theoretical model to assess the reflected sound pressure and particles velocity fields by a microperforated panel backed by a honeycomb layer or by a simple air layer, as well as the angle of reflection, is reported. The theoretical method has been validated by means of experimental measurements in free field and numerical finite element simulations. Results highlight significant differences between MPPS in the case of honeycomb layer or when a simple air cavity is considered. Measurements performed in reverberation chamber and standing wave tube for the same micro-perforated panel have been carried out as well, allowing a further validation of the theoretical model. The latter measurements make possible, at the same time, experimentally appreciate the differences of the absorption coefficient values with and without honeycomb layer, in the case of normal, oblique and diffuse sound incidence.
{"title":"Reflected sound field over microperforated panel systems","authors":"Raffaele Dragonetti , Elio Di Giulio , Annunziata Bruno , Antonio Scofano , Rosario Aniello Romano","doi":"10.1016/j.apacoust.2025.110628","DOIUrl":"10.1016/j.apacoust.2025.110628","url":null,"abstract":"<div><div>In this paper the reflected sound field over micro-perforated systems (MPPS) is investigated by using experimental, numerical and theoretical approaches. Two types of MPPS configurations are considered: one with an air cavity termination and the other with a honeycomb layer termination. A theoretical model to assess the reflected sound pressure and particles velocity fields by a microperforated panel backed by a honeycomb layer or by a simple air layer, as well as the angle of reflection, is reported. The theoretical method has been validated by means of experimental measurements in free field and numerical finite element simulations. Results highlight significant differences between MPPS in the case of honeycomb layer or when a simple air cavity is considered. Measurements performed in reverberation chamber and standing wave tube for the same micro-perforated panel have been carried out as well, allowing a further validation of the theoretical model. The latter measurements make possible, at the same time, experimentally appreciate the differences of the absorption coefficient values with and without honeycomb layer, in the case of normal, oblique and diffuse sound incidence.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110628"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-14DOI: 10.1016/j.apacoust.2025.110676
Yonghui Zhang, Lei Zhang, Youdong Duan, Xiaoming Zhou
Ventilation structures supported by the Fano-like interference can act as high-performance sound silencers, yet the bandwidth gets limited eventually by coexisting resonant transmission. In this work, we focus on the space-coiling ventilation structure, and overcome the limitation by introducing a cylindrical shell made of microperforated panels (MPPs) in between the channel and ventilation pipe. The underlying mechanism is due to the resonance-induced field intensity enhancement within coiling channels, which can produce a significant pressure difference on both sides of the MPP to damp resonant acoustic transmission. Based on this behavior, broadband sound reduction with the bandwidth exceeding an octave can be achieved when two such structural elements are cascaded. Enhanced acoustic damping by MPPs and broadband sound reduction in bi-cell structures are numerically analyzed and validated experimentally.
{"title":"Broadband sound reduction in space-coiling ventilation structures with microperforated shells","authors":"Yonghui Zhang, Lei Zhang, Youdong Duan, Xiaoming Zhou","doi":"10.1016/j.apacoust.2025.110676","DOIUrl":"10.1016/j.apacoust.2025.110676","url":null,"abstract":"<div><div>Ventilation structures supported by the Fano-like interference can act as high-performance sound silencers, yet the bandwidth gets limited eventually by coexisting resonant transmission. In this work, we focus on the space-coiling ventilation structure, and overcome the limitation by introducing a cylindrical shell made of microperforated panels (MPPs) in between the channel and ventilation pipe. The underlying mechanism is due to the resonance-induced field intensity enhancement within coiling channels, which can produce a significant pressure difference on both sides of the MPP to damp resonant acoustic transmission. Based on this behavior, broadband sound reduction with the bandwidth exceeding an octave can be achieved when two such structural elements are cascaded. Enhanced acoustic damping by MPPs and broadband sound reduction in bi-cell structures are numerically analyzed and validated experimentally.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110676"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-14DOI: 10.1016/j.apacoust.2025.110679
Rui Wang , Shuai Tang , Jingkun Zhan , Cheng Lü , Jiabao Yao , Wencong Zhang , Jiabin Hou , Guorong Cui , Qiang Zhang
In this work, a broadband acoustic beam splitter that has an asymmetric transmission feature is proposed by constructing a dissipative acoustic coupler. The beam splitter has a simple configuration, requiring only three straight air cavities and two space-independent air slits. The dissipation just needs to be uniformly exerted into the middle cavity, and thus the complicated modulation of the loss factor is avoided. The acoustic waves incident from one-side of a certain cavity exhibit an equal-weighted intensity distribution along top and bottom cavities, while those cannot transfer back to a certain cavity when top and bottom cavities incident from the other side simultaneously. Given the excellent asymmetric wave propagating performance, a one-way acoustic mode converter is further constructed by sealing both sides of the middle cavity. The 0-order acoustic waves can be converted into 1-order acoustic waves unidirectionally in a broadband from 3.8 kHz to 10 kHz. More uniquely, an acoustic metamaterial that has an ability of asymmetric transmission is designed as well by adopting the mode converters as basic meta-atoms, through which the incident waves can split into two parts with opposite directions unidirectionally. By taking advantage of the broadband feature of the metamaterial, the angle of the splitting beam is able to be manipulated flexibly. Our work provides an effective solution for the realization of asymmetric and broadband beam splitting, which may have potential applications in numerous fields such as acoustic detection and acoustic logic operations.
{"title":"Asymmetric generation of broadband beam splitting using a dissipative acoustic coupler-based metamaterial","authors":"Rui Wang , Shuai Tang , Jingkun Zhan , Cheng Lü , Jiabao Yao , Wencong Zhang , Jiabin Hou , Guorong Cui , Qiang Zhang","doi":"10.1016/j.apacoust.2025.110679","DOIUrl":"10.1016/j.apacoust.2025.110679","url":null,"abstract":"<div><div>In this work, a broadband acoustic beam splitter that has an asymmetric transmission feature is proposed by constructing a dissipative acoustic coupler. The beam splitter has a simple configuration, requiring only three straight air cavities and two space-independent air slits. The dissipation just needs to be uniformly exerted into the middle cavity, and thus the complicated modulation of the loss factor is avoided. The acoustic waves incident from one-side of a certain cavity exhibit an equal-weighted intensity distribution along top and bottom cavities, while those cannot transfer back to a certain cavity when top and bottom cavities incident from the other side simultaneously. Given the excellent asymmetric wave propagating performance, a one-way acoustic mode converter is further constructed by sealing both sides of the middle cavity. The 0-order acoustic waves can be converted into 1-order acoustic waves unidirectionally in a broadband from 3.8 kHz to 10 kHz. More uniquely, an acoustic metamaterial that has an ability of asymmetric transmission is designed as well by adopting the mode converters as basic <em>meta</em>-atoms, through which the incident waves can split into two parts with opposite directions unidirectionally. By taking advantage of the broadband feature of the metamaterial, the angle of the splitting beam is able to be manipulated flexibly. Our work provides an effective solution for the realization of asymmetric and broadband beam splitting, which may have potential applications in numerous fields such as acoustic detection and acoustic logic operations.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110679"},"PeriodicalIF":3.4,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143620600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-13DOI: 10.1016/j.apacoust.2025.110674
Rafał Żuchowski, Artur Nowoświat, Michał Marchacz, Marcin Górski
Although expansion joints are an essential element of bridge infrastructure, they cause huge noise problems. Expansion joints can be structured differently whilst also being able to be installed differently. This article presents a case study on expansion joints installed perpendicularly and at an angle to the direction of traffic. It appears that the installation method affects the overall level of sound produced. Differences between diagonal and perpendicular constructions in the direction of traffic reach up to 2.9 dB. This value approximately corresponds to a doubling of the level of noise. The paper also presents a Type B uncertainty assessment for a Class I acoustic metre. The separation of upper and lower bounds of uncertainty is a particularly interesting result. In doing so, it was noted that the interval in which the true value of the measurement is located is asymmetrical. In the case of a type B uncertainty analysis, an upper limit on the expanded uncertainty of and a lower limit of .
{"title":"Noise assessment of expansion joints built perpendicularly and angled in the direction of traffic. Measurement method: Case study","authors":"Rafał Żuchowski, Artur Nowoświat, Michał Marchacz, Marcin Górski","doi":"10.1016/j.apacoust.2025.110674","DOIUrl":"10.1016/j.apacoust.2025.110674","url":null,"abstract":"<div><div>Although expansion joints are an essential element of bridge infrastructure, they cause huge noise problems. Expansion joints can be structured differently whilst also being able to be installed differently. This article presents a case study on expansion joints installed perpendicularly and at an angle to the direction of traffic. It appears that the installation method affects the overall level of sound produced. Differences between diagonal and perpendicular constructions in the direction of traffic reach up to 2.9 dB. This value approximately corresponds to a doubling of the level of noise. The paper also presents a Type B uncertainty assessment for a Class I acoustic metre. The separation of upper and lower bounds of uncertainty is a particularly interesting result. In doing so, it was noted that the interval in which the true value of the measurement is located is asymmetrical. In the case of a type B uncertainty analysis, an upper limit on the expanded uncertainty of <span><math><mrow><msubsup><mi>U</mi><mrow><mi>B</mi><mo>,</mo><mn>95</mn></mrow><mo>+</mo></msubsup><mo>=</mo><mn>1.12</mn><mspace></mspace><mtext>dB</mtext></mrow></math></span> and a lower limit of <span><math><mrow><msubsup><mi>U</mi><mrow><mi>B</mi><mo>,</mo><mn>95</mn></mrow><mo>-</mo></msubsup><mo>=</mo><mo>-</mo><mn>1.22</mn><mspace></mspace><mtext>dB</mtext></mrow></math></span>.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110674"},"PeriodicalIF":3.4,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Personal sound zones allow people in different zones to listen to different audio programs without using headphones. It is proposed in this paper to use the active noise control (ANC) method to create bright and dark zones in car cabins with headrest loudspeakers, and its performance is compared with the most commonly used pressure matching (PM) method. Numerical simulations based on a finite element model of a car cabin show that the ANC method can achieve similar acoustic contrast control performance to that with the PM method with fewer channels, and the adaptive algorithm has the potential to be applied in the system. The experiment results obtained in a mid-trim level A-class sedan are presented to support the findings in the simulations, and subjective experiments are carried out to evaluate the performance of these two methods.
{"title":"Creating personal sound zones in car cabins with active noise control","authors":"Qing Xu, Shuping Wang, Jiancheng Tao, Haishan Zou, Xiaojun Qiu","doi":"10.1016/j.apacoust.2025.110670","DOIUrl":"10.1016/j.apacoust.2025.110670","url":null,"abstract":"<div><div>Personal sound zones allow people in different zones to listen to different audio programs without using headphones. It is proposed in this paper to use the active noise control (ANC) method to create bright and dark zones in car cabins with headrest loudspeakers, and its performance is compared with the most commonly used pressure matching (PM) method. Numerical simulations based on a finite element model of a car cabin show that the ANC method can achieve similar acoustic contrast control performance to that with the PM method with fewer channels, and the adaptive algorithm has the potential to be applied in the system. The experiment results obtained in a mid-trim level A-class sedan are presented to support the findings in the simulations, and subjective experiments are carried out to evaluate the performance of these two methods.</div></div>","PeriodicalId":55506,"journal":{"name":"Applied Acoustics","volume":"235 ","pages":"Article 110670"},"PeriodicalIF":3.4,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143611313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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