This theoretical work discovers four new dispersive shear-horizontal (SH) waves propagating in the transversely isotropic piezoelectromagnetic plate of class 6 mm. In this work, the following mechanical, electrical, and magnetic boundary conditions at both the upper and lower free surfaces of the piezoelectromagnetic plate are utilized: the mechanically free surface, continuity of both the electrical and magnetic potentials, and continuity of both the electrical and magnetic inductions. The solutions for the new SH-wave velocities (dispersion relations) are found in explicit forms and then graphically studied. The graphical investigation has soundly illuminated several interesting peculiarities that were also discussed. The piezoelectromagnetic materials, also known as the magnetoelectroelastic media, are famous as smart materials because the electrical subsystem of the materials can interact with the magnetic subsystem via the mechanical subsystem, and vice versa. Therefore, it is very important to know the wave characteristics of such (composite) materials because of possible constitution of new technical devices with a high level of integration. It is obvious that the plate waves can be preferable for further miniaturization of the technical devices and used for the nondestructive testing and evaluation of thin piezoelectromagnetic films.
{"title":"On New Dispersive SH-Waves Propagating in Piezoelectromagnetic Plate","authors":"A. Zakharenko","doi":"10.4236/OJA.2015.53011","DOIUrl":"https://doi.org/10.4236/OJA.2015.53011","url":null,"abstract":"This theoretical work discovers four new dispersive shear-horizontal (SH) waves propagating in the transversely isotropic piezoelectromagnetic plate of class 6 mm. In this work, the following mechanical, electrical, and magnetic boundary conditions at both the upper and lower free surfaces of the piezoelectromagnetic plate are utilized: the mechanically free surface, continuity of both the electrical and magnetic potentials, and continuity of both the electrical and magnetic inductions. The solutions for the new SH-wave velocities (dispersion relations) are found in explicit forms and then graphically studied. The graphical investigation has soundly illuminated several interesting peculiarities that were also discussed. The piezoelectromagnetic materials, also known as the magnetoelectroelastic media, are famous as smart materials because the electrical subsystem of the materials can interact with the magnetic subsystem via the mechanical subsystem, and vice versa. Therefore, it is very important to know the wave characteristics of such (composite) materials because of possible constitution of new technical devices with a high level of integration. It is obvious that the plate waves can be preferable for further miniaturization of the technical devices and used for the nondestructive testing and evaluation of thin piezoelectromagnetic films.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"05 1","pages":"122-137"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70558013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Kobayashi, Kaho Shimakage, Chiemi Honma, H. Matsumoto, K. Otake, A. Shono
The ultrasonic degradation of methylene blue at a frequency of 490 kHz was carried out in the absence and presence of TiO2 or Al2O3 particle, and the effects of amounts of particle on the enhancement of degradation rate constant estimated by assuming first-order-kinetics were investigated. The degradation reaction was enhanced by particle addition, and the apparent degradation rate constant is proportional to the increase in amount of particle. In addition, the constant of proportionality is not influenced by degraded material and ultrasonic frequency. However, particle type influences the constant of proportionality, and the value of TiO2 particle is about 6 times as large as that of Al2O3 particle.
{"title":"Effect of Particle Addition on Ultrasonic Degradation Reaction Rate","authors":"D. Kobayashi, Kaho Shimakage, Chiemi Honma, H. Matsumoto, K. Otake, A. Shono","doi":"10.4236/OJA.2015.53006","DOIUrl":"https://doi.org/10.4236/OJA.2015.53006","url":null,"abstract":"The ultrasonic degradation of methylene blue at a frequency of 490 kHz was carried out in the absence and presence of TiO2 or Al2O3 particle, and the effects of amounts of particle on the enhancement of degradation rate constant estimated by assuming first-order-kinetics were investigated. The degradation reaction was enhanced by particle addition, and the apparent degradation rate constant is proportional to the increase in amount of particle. In addition, the constant of proportionality is not influenced by degraded material and ultrasonic frequency. However, particle type influences the constant of proportionality, and the value of TiO2 particle is about 6 times as large as that of Al2O3 particle.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"05 1","pages":"67-72"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two additional solutions of new shear-horizontal surface acoustic waves (SH-SAWs) are found in this theoretical report. The SH-SAW propagation is managed by the free surface of a solid when it has a direct contact with a vacuum. The studied smart solid represents the transversely isotropic piezoelectromagnetic (magnetoelectroelastic or MEE) medium that pertains to crystal symmetry class 6 mm. In the developed theoretical treatment, the solid surface must be mechanically free. Also, the magnetic and electrical boundary conditions at the common interface between a vacuum and the solid surface read: the magnetic and electrical displacements must continue and the same for the magnetic and electrical potentials. To obtain these two new SH-SAW solutions, the natural coupling mechanisms such as eμ-hα and eμ-α2 present in the coefficient of the magnetoelectromechanical coupling (CMEMC) can be exploited. Based on the obtained theoretical results, it is possible that a set of technical devices (filters, sensors, delay lines, lab-on-a-chip, etc.) based on smart MEE media can be developed. It is also blatant that the obtained theoretical results can be helpful for the further theoretical and experimental studies on the propagation of the plate SH-waves and the interfacial SH-waves in the MEE (composite) media. The most important issue can be the influence of the magnetoelectric effect on the SH-wave propagation. One must also be familiar with the fact that the surface, interfacial, and plate SH-waves can frequently represent a common tool for nondestructive testing and evaluation of surfaces, interfaces, and plates, respectively.
{"title":"A Study of New Nondispersive SH-SAWs in Magnetoelectroelastic Medium of Symmetry Class 6 mm","authors":"A. Zakharenko","doi":"10.4236/OJA.2015.53009","DOIUrl":"https://doi.org/10.4236/OJA.2015.53009","url":null,"abstract":"Two additional solutions of new shear-horizontal surface acoustic waves (SH-SAWs) are found in this theoretical report. The SH-SAW propagation is managed by the free surface of a solid when it has a direct contact with a vacuum. The studied smart solid represents the transversely isotropic piezoelectromagnetic (magnetoelectroelastic or MEE) medium that pertains to crystal symmetry class 6 mm. In the developed theoretical treatment, the solid surface must be mechanically free. Also, the magnetic and electrical boundary conditions at the common interface between a vacuum and the solid surface read: the magnetic and electrical displacements must continue and the same for the magnetic and electrical potentials. To obtain these two new SH-SAW solutions, the natural coupling mechanisms such as eμ-hα and eμ-α2 present in the coefficient of the magnetoelectromechanical coupling (CMEMC) can be exploited. Based on the obtained theoretical results, it is possible that a set of technical devices (filters, sensors, delay lines, lab-on-a-chip, etc.) based on smart MEE media can be developed. It is also blatant that the obtained theoretical results can be helpful for the further theoretical and experimental studies on the propagation of the plate SH-waves and the interfacial SH-waves in the MEE (composite) media. The most important issue can be the influence of the magnetoelectric effect on the SH-wave propagation. One must also be familiar with the fact that the surface, interfacial, and plate SH-waves can frequently represent a common tool for nondestructive testing and evaluation of surfaces, interfaces, and plates, respectively.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"476 1","pages":"95-111"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper is proposed to consider the propagation of sound waves in the liquid as a result of special deformation of the medium. Mechanical vibrations of the membrane, (diaphragm) creating a sound wave, transfer from layer to layer in medium without causing synchronous oscillations of the fluid particles. It can be assumed that the deformation of the liquid is similar to the driving force (pressure) in the direction perpendicular to the plane of the vibrating membrane. Usually, the running wave functions are used to describe the sound waves, but they do not contain the direction of propagation. It is proposed to consider that the amplitude of the wave is a vector coinciding with the vector tangent to the path of the wave. This would allow for a change of direction of propagation without changing its phase, in which the direction of wave is not present. It proposed a method of calculating a vector of amplitudes of the reflected and transmitted sound waves based on the laws of conservation of impulse and energy of the waves and the boundary conditions defined by Snell’s law. It is shown that one of the two solutions of the wave equation does not apply to real physical process of sound wave’s propagation in the liquid.
{"title":"To the Question of Sound Waves Propagation in Liquid","authors":"V. Ivanov, G. K. Ivanova","doi":"10.4236/OJA.2015.53010","DOIUrl":"https://doi.org/10.4236/OJA.2015.53010","url":null,"abstract":"This paper is proposed to consider the propagation of sound waves in the liquid as a result of special deformation of the medium. Mechanical vibrations of the membrane, (diaphragm) creating a sound wave, transfer from layer to layer in medium without causing synchronous oscillations of the fluid particles. It can be assumed that the deformation of the liquid is similar to the driving force (pressure) in the direction perpendicular to the plane of the vibrating membrane. Usually, the running wave functions are used to describe the sound waves, but they do not contain the direction of propagation. It is proposed to consider that the amplitude of the wave is a vector coinciding with the vector tangent to the path of the wave. This would allow for a change of direction of propagation without changing its phase, in which the direction of wave is not present. It proposed a method of calculating a vector of amplitudes of the reflected and transmitted sound waves based on the laws of conservation of impulse and energy of the waves and the boundary conditions defined by Snell’s law. It is shown that one of the two solutions of the wave equation does not apply to real physical process of sound wave’s propagation in the liquid.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"5 1","pages":"112-121"},"PeriodicalIF":0.0,"publicationDate":"2015-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-08-12DOI: 10.12677/OJAV.2015.32002
黄从兵, 宦洪彬, 刘衍华, 王琦
利用冯∙卡门薄膜大挠度理论，结合达朗贝尔原理，建立正交异性张拉平面膜结构非线性自由振动的控制方程。然后利用伽辽金法对其进行简化，并采用同伦摄动法进行求解，得到振动频率的近似解析解。通过算例，计算了结构的非线性振动频率，并将本文结果与精确解进行比较分析。分析表明：本文所求得的近似解析解与精确解之间的最大误差小于4%。因此本文的近似解析解与精确解非常接近，且本文所得解形式更为简单，计算也更方便，有利于在工程中进行推广应用。 The nonlinear free vibration governing differential equations for the orthotropic tensioned plane membrane structure are established by Von Karman’s membrane large deflection theory and D’Alembert’s principle. Then the governing differential equations are simplified by Bubnov-Ga- lerkin method and solved by the homotopy perturbation method (HPM), and obtained the ap-proximate analytical solution of the vibration frequency. In the computational example, the non-linear vibration frequency of the structure is computed, and the results of this paper are analyzed and compared with the exact solution. The analysis shows that the approximate analytical solution obtained in this paper is very close to the exact solution (the maximum error is less than 4%), and the approximate analytical solution obtained in this paper is more simple and convenient. This is favorable for the popularization and application in engineering.
利用冯∙卡门薄膜大挠度理论，结合达朗贝尔原理，建立正交异性张拉平面膜结构非线性自由振动的控制方程。然后利用伽辽金法对其进行简化，并采用同伦摄动法进行求解，得到振动频率的近似解析解。通过算例，计算了结构的非线性振动频率，并将本文结果与精确解进行比较分析。分析表明：本文所求得的近似解析解与精确解之间的最大误差小于4%。因此本文的近似解析解与精确解非常接近，且本文所得解形式更为简单，计算也更方便，有利于在工程中进行推广应用。 The nonlinear free vibration governing differential equations for the orthotropic tensioned plane membrane structure are established by Von Karman’s membrane large deflection theory and D’Alembert’s principle. Then the governing differential equations are simplified by Bubnov-Ga- lerkin method and solved by the homotopy perturbation method (HPM), and obtained the ap-proximate analytical solution of the vibration frequency. In the computational example, the non-linear vibration frequency of the structure is computed, and the results of this paper are analyzed and compared with the exact solution. The analysis shows that the approximate analytical solution obtained in this paper is very close to the exact solution (the maximum error is less than 4%), and the approximate analytical solution obtained in this paper is more simple and convenient. This is favorable for the popularization and application in engineering.
{"title":"张拉平面膜结构非线性振动频率计算分析 Computation and Analysis for the Frequency of Nonlinear Vibration of Tensioned Plane Membrane Structure","authors":"黄从兵, 宦洪彬, 刘衍华, 王琦","doi":"10.12677/OJAV.2015.32002","DOIUrl":"https://doi.org/10.12677/OJAV.2015.32002","url":null,"abstract":"利用冯∙卡门薄膜大挠度理论，结合达朗贝尔原理，建立正交异性张拉平面膜结构非线性自由振动的控制方程。然后利用伽辽金法对其进行简化，并采用同伦摄动法进行求解，得到振动频率的近似解析解。通过算例，计算了结构的非线性振动频率，并将本文结果与精确解进行比较分析。分析表明：本文所求得的近似解析解与精确解之间的最大误差小于4%。因此本文的近似解析解与精确解非常接近，且本文所得解形式更为简单，计算也更方便，有利于在工程中进行推广应用。 The nonlinear free vibration governing differential equations for the orthotropic tensioned plane membrane structure are established by Von Karman’s membrane large deflection theory and D’Alembert’s principle. Then the governing differential equations are simplified by Bubnov-Ga- lerkin method and solved by the homotopy perturbation method (HPM), and obtained the ap-proximate analytical solution of the vibration frequency. In the computational example, the non-linear vibration frequency of the structure is computed, and the results of this paper are analyzed and compared with the exact solution. The analysis shows that the approximate analytical solution obtained in this paper is very close to the exact solution (the maximum error is less than 4%), and the approximate analytical solution obtained in this paper is more simple and convenient. This is favorable for the popularization and application in engineering.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"5 1","pages":"7-16"},"PeriodicalIF":0.0,"publicationDate":"2015-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-30DOI: 10.12677/OJAV.2015.31001
魏彪, 程尊伟, 杨峰, 吴敬飞, 冯鹏
本文在阐述了微差爆破中常用的预测爆破装药量经验公式及其分析损坏建筑物的主要因素基础上，针对目前预测爆破装药量方法的不足，提出了一种综合振动强度和主振频率预测爆破装药量的新方法。研究结果表明，通过对GB6722—2003《爆破安全规程》做线性化处理，得到主振频率与装药量之间的关系，由此得出了最大爆破装药量的计算公式。最后，结合实际工程事例，对所得到的新方法进行了实验验证。本文对降低工程爆破危害具有一定的参考价值。 Based on the empirical formula of millisecond blasting charge weight prediction and main factors leading to building damage, considering the shortage of charge weight prediction, a new method involving either vibration intensity or main vibration frequency is obtained. The results show that after linearizing the GB6722—2003 Blasting Safety Regulations, we can get the relationship be-tween vibration intensity and main vibration frequency, and thus formula of calculating the max-imum charge weight is given. Finally, combining with practical engineering to verify the applica-bility of the formula, this paper has some reference value for reducing the damage of engineering blasting.
本文在阐述了微差爆破中常用的预测爆破装药量经验公式及其分析损坏建筑物的主要因素基础上，针对目前预测爆破装药量方法的不足，提出了一种综合振动强度和主振频率预测爆破装药量的新方法。研究结果表明，通过对GB6722—2003《爆破安全规程》做线性化处理，得到主振频率与装药量之间的关系，由此得出了最大爆破装药量的计算公式。最后，结合实际工程事例，对所得到的新方法进行了实验验证。本文对降低工程爆破危害具有一定的参考价值。 Based on the empirical formula of millisecond blasting charge weight prediction and main factors leading to building damage, considering the shortage of charge weight prediction, a new method involving either vibration intensity or main vibration frequency is obtained. The results show that after linearizing the GB6722—2003 Blasting Safety Regulations, we can get the relationship be-tween vibration intensity and main vibration frequency, and thus formula of calculating the max-imum charge weight is given. Finally, combining with practical engineering to verify the applica-bility of the formula, this paper has some reference value for reducing the damage of engineering blasting.
{"title":"一种微差爆破装药量振动预测及其在保护建筑物中的应用 Charge Weight Prediction of Millisecond Blasting and Its Application in Building Protection","authors":"魏彪, 程尊伟, 杨峰, 吴敬飞, 冯鹏","doi":"10.12677/OJAV.2015.31001","DOIUrl":"https://doi.org/10.12677/OJAV.2015.31001","url":null,"abstract":"本文在阐述了微差爆破中常用的预测爆破装药量经验公式及其分析损坏建筑物的主要因素基础上，针对目前预测爆破装药量方法的不足，提出了一种综合振动强度和主振频率预测爆破装药量的新方法。研究结果表明，通过对GB6722—2003《爆破安全规程》做线性化处理，得到主振频率与装药量之间的关系，由此得出了最大爆破装药量的计算公式。最后，结合实际工程事例，对所得到的新方法进行了实验验证。本文对降低工程爆破危害具有一定的参考价值。 Based on the empirical formula of millisecond blasting charge weight prediction and main factors leading to building damage, considering the shortage of charge weight prediction, a new method involving either vibration intensity or main vibration frequency is obtained. The results show that after linearizing the GB6722—2003 Blasting Safety Regulations, we can get the relationship be-tween vibration intensity and main vibration frequency, and thus formula of calculating the max-imum charge weight is given. Finally, combining with practical engineering to verify the applica-bility of the formula, this paper has some reference value for reducing the damage of engineering blasting.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"03 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2015-06-08DOI: 10.12677/OJAV.2014.23003
陆蓓, 陈信耀, 刘艳, 田琦
本文介绍了有源噪声控制的应用，并分析了有源噪声控制的基本原理，指出在实际应用中对于无法测得有效的原噪声信号情况中，需要采用反馈控制系统。由于通过自适应反馈控制系统可以避免取得源噪声的相关信号，因而本文对于FXLMS算法进行分析，与传统LMS算法相比，FXLMS算法考虑了牙科设备如电机驱动牙钻或气动涡轮机驱动牙钻中的次级信道并进行了补偿，因而更加适用于牙科领域的自适应有源消声。文中最后对于牙科噪声进行探究，并给出不同参考信号与不同牙科噪声下的仿真结果。 This paper introduces the application of active noise control technology, and analyzes the funda-mental of it. The paper points out that it is necessary to use a feedback control system when the original noise information can’t be reached. Since designing an adaptive feedback system can meet this requirement, the paper focuses on the FXLMS algorithm. Compared with traditional LMS algo-rithm, FXLMS algorithm can compensate the second channel in the dental device such as electro-motor driven dental drill or air turbine driven drill, which LMS algorithm doesn’t take into account. At last, the paper analyzes the dental noise from dental drills and simulates the performance of FXLMS algorithm in different situations, such as different reference signals and different noises.
本文介绍了有源噪声控制的应用，并分析了有源噪声控制的基本原理，指出在实际应用中对于无法测得有效的原噪声信号情况中，需要采用反馈控制系统。由于通过自适应反馈控制系统可以避免取得源噪声的相关信号，因而本文对于FXLMS算法进行分析，与传统LMS算法相比，FXLMS算法考虑了牙科设备如电机驱动牙钻或气动涡轮机驱动牙钻中的次级信道并进行了补偿，因而更加适用于牙科领域的自适应有源消声。文中最后对于牙科噪声进行探究，并给出不同参考信号与不同牙科噪声下的仿真结果。 This paper introduces the application of active noise control technology, and analyzes the funda-mental of it. The paper points out that it is necessary to use a feedback control system when the original noise information can’t be reached. Since designing an adaptive feedback system can meet this requirement, the paper focuses on the FXLMS algorithm. Compared with traditional LMS algo-rithm, FXLMS algorithm can compensate the second channel in the dental device such as electro-motor driven dental drill or air turbine driven drill, which LMS algorithm doesn’t take into account. At last, the paper analyzes the dental noise from dental drills and simulates the performance of FXLMS algorithm in different situations, such as different reference signals and different noises.
{"title":"有源噪声控制在牙科治疗上的应用仿真 Application Simulation of Active Noise Control in Dental Treatment","authors":"陆蓓, 陈信耀, 刘艳, 田琦","doi":"10.12677/OJAV.2014.23003","DOIUrl":"https://doi.org/10.12677/OJAV.2014.23003","url":null,"abstract":"本文介绍了有源噪声控制的应用，并分析了有源噪声控制的基本原理，指出在实际应用中对于无法测得有效的原噪声信号情况中，需要采用反馈控制系统。由于通过自适应反馈控制系统可以避免取得源噪声的相关信号，因而本文对于FXLMS算法进行分析，与传统LMS算法相比，FXLMS算法考虑了牙科设备如电机驱动牙钻或气动涡轮机驱动牙钻中的次级信道并进行了补偿，因而更加适用于牙科领域的自适应有源消声。文中最后对于牙科噪声进行探究，并给出不同参考信号与不同牙科噪声下的仿真结果。 This paper introduces the application of active noise control technology, and analyzes the funda-mental of it. The paper points out that it is necessary to use a feedback control system when the original noise information can’t be reached. Since designing an adaptive feedback system can meet this requirement, the paper focuses on the FXLMS algorithm. Compared with traditional LMS algo-rithm, FXLMS algorithm can compensate the second channel in the dental device such as electro-motor driven dental drill or air turbine driven drill, which LMS algorithm doesn’t take into account. At last, the paper analyzes the dental noise from dental drills and simulates the performance of FXLMS algorithm in different situations, such as different reference signals and different noises.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"02 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66176964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work the turbulence based acoustic sources and the corresponding wave propagation of fluctuating flow values in incompressible fluid flows are considered. Lighthill’s and Curle’s acoustic analogies are implemented in the open source computational fluid dynamics framework OpenFOAM. The main objective of this work is to visualize and localize the dominated sound sources and the resulting values of fluctuating pressure values within the computation domain representing the acoustical near field. This is all done on one mesh and during the iterative computation of the transient fluid flow. Finally the flow field and acoustical results of different simulation cases are presented and the properties of the shown method are discussed.
{"title":"Implementation of Acoustic Analogies in OpenFOAM for Computation of Sound Fields","authors":"J. Schmalz, W. Kowalczyk","doi":"10.4236/OJA.2015.52004","DOIUrl":"https://doi.org/10.4236/OJA.2015.52004","url":null,"abstract":"In this work the turbulence based acoustic sources and the corresponding wave propagation of fluctuating flow values in incompressible fluid flows are considered. Lighthill’s and Curle’s acoustic analogies are implemented in the open source computational fluid dynamics framework OpenFOAM. The main objective of this work is to visualize and localize the dominated sound sources and the resulting values of fluctuating pressure values within the computation domain representing the acoustical near field. This is all done on one mesh and during the iterative computation of the transient fluid flow. Finally the flow field and acoustical results of different simulation cases are presented and the properties of the shown method are discussed.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"05 1","pages":"29-44"},"PeriodicalIF":0.0,"publicationDate":"2015-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, we try to use the coating of effective electrode surface and change the direction of polarization to design the mode shape piezoelectric motors of the first three modes. We also com-pare the gain of the mode shape piezoelectric motors with respect to the normal shape piezoelectric motor, including rotational speed, loading ability, torque, phase angle conversion and efficiency. According to the results of theoretical and simulation analysis, we have found that the gain of the mode shape piezoelectric stators are larger than the normal shape piezoelectric stator on average. According to the results of experiments, we found that the gain of the rotational speed, loading ability, torque, driving phase angle conversion and efficiency of the mode shape (MS1 - 3) piezoelectric motors are higher than the normal shape piezoelectric motor (NS) under driving condition of the second vibration mode. Also, the gain of the rotational speed and loading ability of the mode shape 2 (MS2) piezoelectric motor are higher than other shapes piezoelectric motors (NS, MS1 and MS3) under driving condition of the second vibration mode. The used maximum rotational speed of the mode shape 2 (MS2) piezoelectric motor is up to 946 rpm under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency, 0o driving phase angle and 13.0 gw net weight. The maximum loading ability and torque of the mode shape 2 (MS2) piezoelectric motor is respectively 451 gw and 0.91 mkgw-m under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency, 0o driving phase angle and 173 rpm rotational speed. And the gain of efficiency (output power) and maximum loading ability (torque) of the mode shape 2 (MS2) piezoelectric motor are respectively 2.28 and 1.54 with respect to the normal shape piezoelectric motor under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency and 0o driving phase angle. According to the results of the experiments, we have finally found that the piezoelectric motors (NS and MS1 - 3) can be driven only by the second vibration mode because the stator can produce elliptical motion and allows the rotor to generate orientation rotation. However, the first vibration mode can allow the rotor to be rotated very fast but it can’t make the rotation of the rotor orientation. Furthermore, we also found that the rotor can’t rotate by the third vibration mode because its vibration energy is absorbed by the structure itself, so causing the rotor stagnation.
{"title":"A Study on the Mode Shape Piezoelectric Motor","authors":"J. Jou","doi":"10.4236/OJA.2015.52005","DOIUrl":"https://doi.org/10.4236/OJA.2015.52005","url":null,"abstract":"In this paper, we try to use the coating of effective electrode surface and change the direction of polarization to design the mode shape piezoelectric motors of the first three modes. We also com-pare the gain of the mode shape piezoelectric motors with respect to the normal shape piezoelectric motor, including rotational speed, loading ability, torque, phase angle conversion and efficiency. According to the results of theoretical and simulation analysis, we have found that the gain of the mode shape piezoelectric stators are larger than the normal shape piezoelectric stator on average. According to the results of experiments, we found that the gain of the rotational speed, loading ability, torque, driving phase angle conversion and efficiency of the mode shape (MS1 - 3) piezoelectric motors are higher than the normal shape piezoelectric motor (NS) under driving condition of the second vibration mode. Also, the gain of the rotational speed and loading ability of the mode shape 2 (MS2) piezoelectric motor are higher than other shapes piezoelectric motors (NS, MS1 and MS3) under driving condition of the second vibration mode. The used maximum rotational speed of the mode shape 2 (MS2) piezoelectric motor is up to 946 rpm under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency, 0o driving phase angle and 13.0 gw net weight. The maximum loading ability and torque of the mode shape 2 (MS2) piezoelectric motor is respectively 451 gw and 0.91 mkgw-m under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency, 0o driving phase angle and 173 rpm rotational speed. And the gain of efficiency (output power) and maximum loading ability (torque) of the mode shape 2 (MS2) piezoelectric motor are respectively 2.28 and 1.54 with respect to the normal shape piezoelectric motor under conditions of 180 Vp-p driving voltage, 10.7 kHz driving frequency and 0o driving phase angle. According to the results of the experiments, we have finally found that the piezoelectric motors (NS and MS1 - 3) can be driven only by the second vibration mode because the stator can produce elliptical motion and allows the rotor to generate orientation rotation. However, the first vibration mode can allow the rotor to be rotated very fast but it can’t make the rotation of the rotor orientation. Furthermore, we also found that the rotor can’t rotate by the third vibration mode because its vibration energy is absorbed by the structure itself, so causing the rotor stagnation.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"05 1","pages":"46-65"},"PeriodicalIF":0.0,"publicationDate":"2015-06-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. R. Lisboa, José Cataldo Ottieri, Alice Elizabeth González
The analysis of acoustic emissions generated by the interaction between the wind and a building’s facade of approximately 90 m high, located in the city of Montevideo, is presented. There is a helipad on the roof of the building. It is surrounded by a perforated plate (4.87 m high). Once the building was finished, complaints about the noise annoyance were expressed by some neighbors and working population in the building. Measurements of sound pressure levels on the site have been done. Also the possible acoustic sources were physically characterized. The noise source was identified: the acoustical emissions were associated with a phenomenon caused by wind speeds above 20 m/s from different directions, generating high sounds pressure levels in octave band of 4000 Hz, after its passage through the perforated plate on the contour of the roof. These studies were complemented by measurements in wind tunnel using a physical model built with the same plate installed in the building, which allowed verifying the results.
{"title":"Noise Annoyance Due to Wind Flow Interaction with a Building’s Facade","authors":"M. R. Lisboa, José Cataldo Ottieri, Alice Elizabeth González","doi":"10.4236/OJA.2015.51001","DOIUrl":"https://doi.org/10.4236/OJA.2015.51001","url":null,"abstract":"The analysis of acoustic emissions generated by the interaction between the wind and a building’s facade of approximately 90 m high, located in the city of Montevideo, is presented. There is a helipad on the roof of the building. It is surrounded by a perforated plate (4.87 m high). Once the building was finished, complaints about the noise annoyance were expressed by some neighbors and working population in the building. Measurements of sound pressure levels on the site have been done. Also the possible acoustic sources were physically characterized. The noise source was identified: the acoustical emissions were associated with a phenomenon caused by wind speeds above 20 m/s from different directions, generating high sounds pressure levels in octave band of 4000 Hz, after its passage through the perforated plate on the contour of the roof. These studies were complemented by measurements in wind tunnel using a physical model built with the same plate installed in the building, which allowed verifying the results.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"05 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2015-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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