Pub Date : 2023-11-29DOI: 10.24425/aoa.2023.146643
Jiaman Du, Zilong Peng, GE Lili, S. Lyu, Fulin Zhou, Yan Liu
,
,
{"title":"Modulation Mechanism of Acoustic Scattering in Underwater Corner Reflectors with Acoustic Metasurfaces","authors":"Jiaman Du, Zilong Peng, GE Lili, S. Lyu, Fulin Zhou, Yan Liu","doi":"10.24425/aoa.2023.146643","DOIUrl":"https://doi.org/10.24425/aoa.2023.146643","url":null,"abstract":",","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139211490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-29DOI: 10.24425/aoa.2023.146812
LI Bing, Fu-lin Zhou, Jun Fan, Bin Wang, Liwen Tan, P. R. China
For a simplified sonar dome model, an optimization method for internal gradients of functionally graded material (FGM) acoustic windows is proposed in this paper. This method can be used to design optimized FGM acoustic windows with better turbulent self-noise suppression and sound transmission performances. A theoretical model of FGM acoustic windows to evaluate the reduction of self-noise caused by the turbulent boundary layer (TBL) pulsating pressure and the sound transmission loss (STL) is derived through the double Fourier transform and the wavenumber frequency spectrum analysis, respectively, based on the transfer matrix idea and the classical elastic theory. The accuracy of the theory is verified by the finite element results of COMSOL Multiphysics. Utilizing the genetic algorithm (GA) and taking the monotonic gradient as the constraint condition, the internal gradient optimization method of FGM acoustic windows obtains the optimization variables in the Bernstein polynomial when the optimization objective is minimized by iterating the optimization variables in the deviation function represented by the Bernstein polynomial that is introduced in the gradient function. The STL, the turbulent self-noise reduction or a weighting function of the STL and turbulent self-noise reduction of FGM acoustic windows is chosen as the optimization objective. The optimization calculation of the sound transmission or turbulent self-noise suppression performances is carried out for the FRP-rubber FGM (FGM with fiber reinforced plastic (FRP) as the substrate material and rubber as the top material) acoustic window. The optimized results show that both the sound transmission and turbulent self-noise suppression performance are effectively improved, which verifies the effectiveness of the optimization method. Finally, the mechanism of the sound transmission and self-noise suppression characteristics before and after optimization are explained and analyzed based on the equivalent model of graded materials. The research results of this paper provide a reference value for the future design of FGM acoustic windows for sonar domes.
{"title":"Research on the Performance Optimization of Turbulent Self-Noise Suppression and Sound Transmission of Acoustic Windows Made from Functionally Graded Material","authors":"LI Bing, Fu-lin Zhou, Jun Fan, Bin Wang, Liwen Tan, P. R. China","doi":"10.24425/aoa.2023.146812","DOIUrl":"https://doi.org/10.24425/aoa.2023.146812","url":null,"abstract":"For a simplified sonar dome model, an optimization method for internal gradients of functionally graded material (FGM) acoustic windows is proposed in this paper. This method can be used to design optimized FGM acoustic windows with better turbulent self-noise suppression and sound transmission performances. A theoretical model of FGM acoustic windows to evaluate the reduction of self-noise caused by the turbulent boundary layer (TBL) pulsating pressure and the sound transmission loss (STL) is derived through the double Fourier transform and the wavenumber frequency spectrum analysis, respectively, based on the transfer matrix idea and the classical elastic theory. The accuracy of the theory is verified by the finite element results of COMSOL Multiphysics. Utilizing the genetic algorithm (GA) and taking the monotonic gradient as the constraint condition, the internal gradient optimization method of FGM acoustic windows obtains the optimization variables in the Bernstein polynomial when the optimization objective is minimized by iterating the optimization variables in the deviation function represented by the Bernstein polynomial that is introduced in the gradient function. The STL, the turbulent self-noise reduction or a weighting function of the STL and turbulent self-noise reduction of FGM acoustic windows is chosen as the optimization objective. The optimization calculation of the sound transmission or turbulent self-noise suppression performances is carried out for the FRP-rubber FGM (FGM with fiber reinforced plastic (FRP) as the substrate material and rubber as the top material) acoustic window. The optimized results show that both the sound transmission and turbulent self-noise suppression performance are effectively improved, which verifies the effectiveness of the optimization method. Finally, the mechanism of the sound transmission and self-noise suppression characteristics before and after optimization are explained and analyzed based on the equivalent model of graded materials. The research results of this paper provide a reference value for the future design of FGM acoustic windows for sonar domes.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":"16 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139214965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-29DOI: 10.24425/aoa.2023.146817
{"title":"Janusz Wójcik Professor of the IPPT PAN (In Memoriam)","authors":"","doi":"10.24425/aoa.2023.146817","DOIUrl":"https://doi.org/10.24425/aoa.2023.146817","url":null,"abstract":"","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":"48 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139210238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-11-29DOI: 10.24425/aoa.2023.146818
Agnieszka Ozga, Jacek Wierzbicki, Dominik Mleczko
The research concerning the future of sound in towns and cities is focused on two main issues: studies are conducted separately on the comfort, i.e., assessment of visual scenery and sound levels in a cityscape and separately, on the health protection issues. The policy of the acoustic environment control with regard to the health of its inhabitants is traditionally connected with measurements of noise levels presented with the help of the coefficients L den and L night noise indicators, while the models based on tranquillity rating (TR) with the help of the coefficients L Amax , L Amin , L Aeq , L A10 . None of these coefficients refers to the soundscape. In this paper, we present a justification of the necessity to enter into discussion on the need to combine these research areas. The authorities managing towns and cities of the future should be provided with tools enabling them to assess modernisation projects from the point of view of both health and comfort of inhabitants. We present our ideas treating them as an invitation to a scientific discourse, in the form of analysis of actual projects concerning modification of existing cityscapes. The modifications are aimed at returning some unfavourably developed spaces to the inhabitants. When analysing the changes proposed in the projects, we take into account two models of the revitalised area quality assessment. The first model is used to assess the effect of noise on health. The second model, based on the indicator known as the TR, serves simultaneous assessment of an area from both visual and acoustical aspects. The models used contemporarily by scientists show multiple flaws, therefore, for the TR indicator we propose a modification taking the sound structure into account. The modification embodies the idea of masking unpleasant sounds with friendly ones. The changes to the model are presented, in this paper, in the context of two projects which were worked out in the framework of 12th edition of the intercollegiate workshop cycle The New Cityscapes. In the course of each workshop of the cycle, we combined art, science, and technology in order to seek solutions creating a better future. In view of the importance of this issue and the need to introduce a certain level of universalism, the authors offer an invitation to join a discussion on the future of sound in urban agglomerations.
有关城镇未来声音的研究主要集中在两个问题上：分别研究舒适度，即评估城市景观的视觉效果和声级；分别研究健康保护问题。与居民健康有关的声学环境控制政策传统上与借助系数 L den 和 L night 噪声指标提出的噪声级测量有关，而基于安宁等级（TR）的模型则借助系数 L Amax、L Amin、L Aeq、L A10。这些系数都与声景无关。在本文中，我们提出了将这些研究领域结合起来进行讨论的必要性。未来城镇的管理机构应掌握相关工具，以便从居民健康和舒适的角度评估现代化项目。我们通过对现有城市景观改造的实际项目进行分析，提出了我们的想法，并将其作为科学讨论的邀请函。这些改造项目的目的是将一些不利于发展的空间还给居民。在分析项目中提出的改造建议时，我们考虑了两种活化区域质量评估模型。第一个模型用于评估噪音对健康的影响。第二种模式以称为 TR 的指标为基础，从视觉和声学两个方面同时评估一个区域。科学家们目前使用的模型显示出多种缺陷，因此，我们建议对 TR 指标进行修改，将声音结构考虑在内。这一修改体现了用友好的声音掩盖不愉快声音的理念。本文结合第 12 期校际研讨会 "新城市景观 "中的两个项目，介绍了对模型的修改。在该周期的每个工作坊中，我们都将艺术、科学和技术相结合，以寻求创造更美好未来的解决方案。考虑到这一问题的重要性以及引入一定程度的普遍性的必要性，作者邀请大家参加关于城市群中声音的未来的讨论。
{"title":"A Proposal Concerning Assessment of Alternative Cityscape Designs with Audiovisual Comfort and Health of Inhabitants","authors":"Agnieszka Ozga, Jacek Wierzbicki, Dominik Mleczko","doi":"10.24425/aoa.2023.146818","DOIUrl":"https://doi.org/10.24425/aoa.2023.146818","url":null,"abstract":"The research concerning the future of sound in towns and cities is focused on two main issues: studies are conducted separately on the comfort, i.e., assessment of visual scenery and sound levels in a cityscape and separately, on the health protection issues. The policy of the acoustic environment control with regard to the health of its inhabitants is traditionally connected with measurements of noise levels presented with the help of the coefficients L den and L night noise indicators, while the models based on tranquillity rating (TR) with the help of the coefficients L Amax , L Amin , L Aeq , L A10 . None of these coefficients refers to the soundscape. In this paper, we present a justification of the necessity to enter into discussion on the need to combine these research areas. The authorities managing towns and cities of the future should be provided with tools enabling them to assess modernisation projects from the point of view of both health and comfort of inhabitants. We present our ideas treating them as an invitation to a scientific discourse, in the form of analysis of actual projects concerning modification of existing cityscapes. The modifications are aimed at returning some unfavourably developed spaces to the inhabitants. When analysing the changes proposed in the projects, we take into account two models of the revitalised area quality assessment. The first model is used to assess the effect of noise on health. The second model, based on the indicator known as the TR, serves simultaneous assessment of an area from both visual and acoustical aspects. The models used contemporarily by scientists show multiple flaws, therefore, for the TR indicator we propose a modification taking the sound structure into account. The modification embodies the idea of masking unpleasant sounds with friendly ones. The changes to the model are presented, in this paper, in the context of two projects which were worked out in the framework of 12th edition of the intercollegiate workshop cycle The New Cityscapes. In the course of each workshop of the cycle, we combined art, science, and technology in order to seek solutions creating a better future. In view of the importance of this issue and the need to introduce a certain level of universalism, the authors offer an invitation to join a discussion on the future of sound in urban agglomerations.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":"198 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139211928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-29DOI: 10.24425/aoa.2023.145245
M. Kafil, K. Darabi, S. Ziaei-Rad
The empirical mode decomposition (EMD) algorithm is widely used as an adaptive time-frequency analysis method to decompose nonlinear and non-stationary signals into sets of intrinsic mode functions (IMFs). In the traditional EMD, the lower and upper envelopes should interpolate the minimum and maximum points of the signal, respectively. In this paper, an improved EMD method is proposed based on the new interpolation points, which are special inflection points (SIP n ) of the signal. These points are identified in the signal and its first ( n − 1 ) derivatives and are considered as auxiliary interpolation points in addition to the extrema. Therefore, the upper and lower envelopes should not only pass through the extrema but also these SIP n sets of points. By adding each set of SIP i ( i = 1 , 2 ,...,n ) to the interpolation points, the frequency resolution of EMD is improved to a certain extent. The effectiveness of the proposed SIP n -EMD is validated by the decomposition of synthetic and experimental bearing vibration signals.
{"title":"An Improved EMD Method Based on Utilizing Certain Inflection Points in the Construction of Envelope Curves","authors":"M. Kafil, K. Darabi, S. Ziaei-Rad","doi":"10.24425/aoa.2023.145245","DOIUrl":"https://doi.org/10.24425/aoa.2023.145245","url":null,"abstract":"The empirical mode decomposition (EMD) algorithm is widely used as an adaptive time-frequency analysis method to decompose nonlinear and non-stationary signals into sets of intrinsic mode functions (IMFs). In the traditional EMD, the lower and upper envelopes should interpolate the minimum and maximum points of the signal, respectively. In this paper, an improved EMD method is proposed based on the new interpolation points, which are special inflection points (SIP n ) of the signal. These points are identified in the signal and its first ( n − 1 ) derivatives and are considered as auxiliary interpolation points in addition to the extrema. Therefore, the upper and lower envelopes should not only pass through the extrema but also these SIP n sets of points. By adding each set of SIP i ( i = 1 , 2 ,...,n ) to the interpolation points, the frequency resolution of EMD is improved to a certain extent. The effectiveness of the proposed SIP n -EMD is validated by the decomposition of synthetic and experimental bearing vibration signals.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43188340","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-29DOI: 10.24425/aoa.2023.145243
P. Lindh, Polina Lemenkova
In this research project, the measurements of the ultrasonic P-and S-waves and seismic cone penetration testing (CPT) were applied to identify subsurface conditions and properties of clayey soil stabilized with lime/cement columns in the Stockholm Norvik Port, Sweden. Applied geophysical methods enabled to identify a connection between the resistance of soil and strength in the stabilized columns. The records of the seismic tests were obtained in the laboratory of Swedish Geotechnical Institute (SGI) through estimated P-and S-wave velocities using techniques of resonance frequency measurement of the stabilized specimens. The CPT profiles were used to evaluate the quality of the lime/cement columns of the reinforced soil by the interpretation of signals. The relationship between the P-and S-waves demonstrated a gain in strength during soil hardening. The quality of soil was evaluated by seismic measurements with aim to achieve sufficient strength of foundations prior to the construction of the infrastructure objects and industrial works. Seismic CPT is an effective method essential to evaluate the correct placement of the CPT inside the column. This work demonstrated the alternative seismic methods supporting the up-hole technology of drilling techniques for practical purpose in civil engineering and geotechnical works.
{"title":"Ultrasonic P- and S-Wave Reflection and CPT Soundings for Measuring Shear Strength in Soil Stabilized by Deep Lime/Cement Columns in Stockholm Norvik Port","authors":"P. Lindh, Polina Lemenkova","doi":"10.24425/aoa.2023.145243","DOIUrl":"https://doi.org/10.24425/aoa.2023.145243","url":null,"abstract":"In this research project, the measurements of the ultrasonic P-and S-waves and seismic cone penetration testing (CPT) were applied to identify subsurface conditions and properties of clayey soil stabilized with lime/cement columns in the Stockholm Norvik Port, Sweden. Applied geophysical methods enabled to identify a connection between the resistance of soil and strength in the stabilized columns. The records of the seismic tests were obtained in the laboratory of Swedish Geotechnical Institute (SGI) through estimated P-and S-wave velocities using techniques of resonance frequency measurement of the stabilized specimens. The CPT profiles were used to evaluate the quality of the lime/cement columns of the reinforced soil by the interpretation of signals. The relationship between the P-and S-waves demonstrated a gain in strength during soil hardening. The quality of soil was evaluated by seismic measurements with aim to achieve sufficient strength of foundations prior to the construction of the infrastructure objects and industrial works. Seismic CPT is an effective method essential to evaluate the correct placement of the CPT inside the column. This work demonstrated the alternative seismic methods supporting the up-hole technology of drilling techniques for practical purpose in civil engineering and geotechnical works.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45932607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-29DOI: 10.24425/aoa.2023.145238
Li Ming, Jizhou Liu
Traffic noise in big cities impacts the people who live and work in high-rise buildings alongside arterial roads. To determine this impact magnitude, this paper proposes and validates a microscopic level method that locally predicts the total noise level and the spectral characteristics of traffic flow in the near-road region. In the proposed method, the vehicles on the road are considered as multiple queues of moving point sound sources with ground reflection considered. To account for the flow of vehicles on the road, traffic field data, and individual vehicle noise source models are also employed. A field measurement is conducted to validate the proposed method. Results comparison shows that the predicted and the measured overall A-weighted sound pressure level and A-weighted noise spectra are within 3 dBA and 5 dBA, respectively. Based on the validated method, the spatial distribution of traffic noise near the arterial road is investigated for different traffic scenarios.
{"title":"A Microscopic Prediction Model for Traffic Noise in Adjacent Regions to Arterial Roads","authors":"Li Ming, Jizhou Liu","doi":"10.24425/aoa.2023.145238","DOIUrl":"https://doi.org/10.24425/aoa.2023.145238","url":null,"abstract":"Traffic noise in big cities impacts the people who live and work in high-rise buildings alongside arterial roads. To determine this impact magnitude, this paper proposes and validates a microscopic level method that locally predicts the total noise level and the spectral characteristics of traffic flow in the near-road region. In the proposed method, the vehicles on the road are considered as multiple queues of moving point sound sources with ground reflection considered. To account for the flow of vehicles on the road, traffic field data, and individual vehicle noise source models are also employed. A field measurement is conducted to validate the proposed method. Results comparison shows that the predicted and the measured overall A-weighted sound pressure level and A-weighted noise spectra are within 3 dBA and 5 dBA, respectively. Based on the validated method, the spatial distribution of traffic noise near the arterial road is investigated for different traffic scenarios.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42963984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-29DOI: 10.24425/aoa.2023.145240
Xiaohui He, Zhongle Liu, Yang Chao, Zhiyong Yuan
In this study, the modified Sauer cavitation model and Kirchhoff-Ffowcs Williams and Hawkings (K-FWH) acoustic model were adopted to numerically simulate the unsteady cavitation flow field and the noise of a three-dimensional NACA66 hydrofoil at a constant cavitation number. The aim of the study is to conduct and analyze the noise performance of a hydrofoil and also determine the characteristics of the sound pressure spectrum, sound power spectrum, and noise changes at different monitoring points. The noise change, sound pressure spectrum, and power spectrum characteristics were estimated at different monitoring points, such as the suction side, pressure side, and tail of the hydrofoil. The noise characteristics and change law of the NACA66 hydrofoil under a constant cavitation number are presented. The results show that hydrofoil cavitation takes on a certain degree of pulsation and periodicity. Under the condition of a constant cavitation number, as the attack angle increases, the cavitation area of the hydrofoil becomes longer and thicker, and the initial position of cavitation moves forward. When the inflow velocity increases, the cavitation noise and the cavitation area change more drastically and have a superposition tendency toward the downstream. The novelty is that the study presents important calculations and analyses regarding the noise performance of a hydrofoil, characteristics of the sound pressure spectrum, and sound power spectrum and noise changes at different monitoring points. The article may be useful for specialists in the field of engineering and physics.
在本研究中，采用改进的Sauer空化模型和Kirchho ffe-Ffowcs-Williams and Hawkins（K-FWH）声学模型对恒定空化数下三维NACA66水翼的非定常空化流场和噪声进行了数值模拟。本研究的目的是进行和分析水翼的噪声性能，并确定不同监测点的声压谱、声功率谱和噪声变化的特征。噪声变化、声压谱和功率谱特性在不同的监测点进行了估计，如水翼的吸力侧、压力侧和尾部。介绍了NACA66水翼在恒定空化数下的噪声特性和变化规律。结果表明，水翼空化具有一定的脉动性和周期性。在空化数不变的情况下，随着攻角的增大，水翼的空化面积变长变厚，空化的初始位置向前移动。当流速增加时，空化噪声和空化面积变化更大，并有向下游叠加的趋势。新颖之处在于，该研究对水翼的噪声性能、声压谱特性、声功率谱以及不同监测点的噪声变化进行了重要的计算和分析。这篇文章可能对工程和物理领域的专家有用。
{"title":"Study on Noise Attenuation Characteristics of Hydrofoil with Specific Cavitation Number","authors":"Xiaohui He, Zhongle Liu, Yang Chao, Zhiyong Yuan","doi":"10.24425/aoa.2023.145240","DOIUrl":"https://doi.org/10.24425/aoa.2023.145240","url":null,"abstract":"In this study, the modified Sauer cavitation model and Kirchhoff-Ffowcs Williams and Hawkings (K-FWH) acoustic model were adopted to numerically simulate the unsteady cavitation flow field and the noise of a three-dimensional NACA66 hydrofoil at a constant cavitation number. The aim of the study is to conduct and analyze the noise performance of a hydrofoil and also determine the characteristics of the sound pressure spectrum, sound power spectrum, and noise changes at different monitoring points. The noise change, sound pressure spectrum, and power spectrum characteristics were estimated at different monitoring points, such as the suction side, pressure side, and tail of the hydrofoil. The noise characteristics and change law of the NACA66 hydrofoil under a constant cavitation number are presented. The results show that hydrofoil cavitation takes on a certain degree of pulsation and periodicity. Under the condition of a constant cavitation number, as the attack angle increases, the cavitation area of the hydrofoil becomes longer and thicker, and the initial position of cavitation moves forward. When the inflow velocity increases, the cavitation noise and the cavitation area change more drastically and have a superposition tendency toward the downstream. The novelty is that the study presents important calculations and analyses regarding the noise performance of a hydrofoil, characteristics of the sound pressure spectrum, and sound power spectrum and noise changes at different monitoring points. The article may be useful for specialists in the field of engineering and physics.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43277413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-29DOI: 10.24425/aoa.2023.145241
A. Brański, Romuald Kuras
The article presents the new 2D asymmetrical PZT (a-PZT) and its effectiveness in the active reduction of triangular plate vibrations. The isosceles right triangular plate with simply supported edges was chosen as the research object. To determine the a-PZT asymmetry and its distribution on the plate, a maximum bending moment criterion for the beam was used. First of all, this criterion points out exact center location of the a-PZT. It was at the point, at which the plate bending moment has reached its maximum value. Next, at this point, it was assumed that the piezoelectric consists of active fibers located radially from the center. Each fiber acted on the plate as a separate actuator. Next, at each direction, the actuator asymmetry was found mathematically by minimizing the amplitude of the vibrations. By connecting the outer edges of individual fibers, the 2D a-PZT was obtained. It was quantitatively confirmed that the effectiveness of the new a-PZT was the best compared with the effectiveness of the standard square and the circular PZTs, adding the same exciting energy to the PZTs.
{"title":"PZT Asymmetrical Shape Optimization in Active Vibration Reduction of Triangular Plates","authors":"A. Brański, Romuald Kuras","doi":"10.24425/aoa.2023.145241","DOIUrl":"https://doi.org/10.24425/aoa.2023.145241","url":null,"abstract":"The article presents the new 2D asymmetrical PZT (a-PZT) and its effectiveness in the active reduction of triangular plate vibrations. The isosceles right triangular plate with simply supported edges was chosen as the research object. To determine the a-PZT asymmetry and its distribution on the plate, a maximum bending moment criterion for the beam was used. First of all, this criterion points out exact center location of the a-PZT. It was at the point, at which the plate bending moment has reached its maximum value. Next, at this point, it was assumed that the piezoelectric consists of active fibers located radially from the center. Each fiber acted on the plate as a separate actuator. Next, at each direction, the actuator asymmetry was found mathematically by minimizing the amplitude of the vibrations. By connecting the outer edges of individual fibers, the 2D a-PZT was obtained. It was quantitatively confirmed that the effectiveness of the new a-PZT was the best compared with the effectiveness of the standard square and the circular PZTs, adding the same exciting energy to the PZTs.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46661962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-08-29DOI: 10.24425/aoa.2023.145242
Ye Chen, Junlin Yang, Li Liang, Shihao Xiao
In order to simplify the motor structure, to reduce the difficulty of rotor pre-pressure application and to obtain better output performance, a new internal cone type rotating traveling wave ultrasonic motor is proposed. The parametric model of the internal cone type ultrasonic motor was established by the ANSYS finite element software. The ultrasonic motor consists of an internal cone type vibrator and a tapered rotor. The dynamic analysis of the motor vibrator is carried out, and two in-plane third-order bending modes with the same frequency and orthogonality are selected as the working modes. The other advantages of this motor are that pre-pressure can be imposed by the weight of the rotor. The prototype was trial-manufactured and experimentally tested for its vibration characteristics and output performance. When the excitation frequency is 22260.0 Hz, the pre-pressure is 0.1 N and the peak-to-peak excitation voltage is 300 V, the maximum output torque of the prototype is 1.06 N ⋅ mm, and the maximum no-load speed can reach 441.2 rpm. The optimal pre-pressure force under different loads is studied, and the influence of the pre-pressure force on the mechanical properties of the ultrasonic motor is analyzed. It is instructive in the practical application of this ultrasonic motor.
{"title":"Design and Experiments of a New Internal Cone Type Traveling Wave Ultrasonic Motor","authors":"Ye Chen, Junlin Yang, Li Liang, Shihao Xiao","doi":"10.24425/aoa.2023.145242","DOIUrl":"https://doi.org/10.24425/aoa.2023.145242","url":null,"abstract":"In order to simplify the motor structure, to reduce the difficulty of rotor pre-pressure application and to obtain better output performance, a new internal cone type rotating traveling wave ultrasonic motor is proposed. The parametric model of the internal cone type ultrasonic motor was established by the ANSYS finite element software. The ultrasonic motor consists of an internal cone type vibrator and a tapered rotor. The dynamic analysis of the motor vibrator is carried out, and two in-plane third-order bending modes with the same frequency and orthogonality are selected as the working modes. The other advantages of this motor are that pre-pressure can be imposed by the weight of the rotor. The prototype was trial-manufactured and experimentally tested for its vibration characteristics and output performance. When the excitation frequency is 22260.0 Hz, the pre-pressure is 0.1 N and the peak-to-peak excitation voltage is 300 V, the maximum output torque of the prototype is 1.06 N ⋅ mm, and the maximum no-load speed can reach 441.2 rpm. The optimal pre-pressure force under different loads is studied, and the influence of the pre-pressure force on the mechanical properties of the ultrasonic motor is analyzed. It is instructive in the practical application of this ultrasonic motor.","PeriodicalId":8149,"journal":{"name":"Archives of Acoustics","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46089809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：