In this work, aqueous glycerol solutions are atomized to investigate the influence of the viscosity on the droplet size and the general atomization behavior in a setup using standing surface acoustic waves (sSAW) and a fluid supply at the boundary of the acoustic path. Depending on the fluid viscosity, the produced aerosols have a monomodal or polymodal size distribution. The mean droplet size in the dominant droplet fraction, however, decreases with increasing viscosity. Our results also indicate that the local wavefield conditions are crucial for the atomization process.
{"title":"Influence of Viscosity in Fluid Atomization with Surface Acoustic Waves","authors":"A. Winkler, P. Bergelt, Lars Hillemann, S. Menzel","doi":"10.4236/OJA.2016.63003","DOIUrl":"https://doi.org/10.4236/OJA.2016.63003","url":null,"abstract":"In this work, aqueous glycerol solutions are atomized to investigate the influence of the viscosity on the droplet size and the general atomization behavior in a setup using standing surface acoustic waves (sSAW) and a fluid supply at the boundary of the acoustic path. Depending on the fluid viscosity, the produced aerosols have a monomodal or polymodal size distribution. The mean droplet size in the dominant droplet fraction, however, decreases with increasing viscosity. Our results also indicate that the local wavefield conditions are crucial for the atomization process.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"20 1","pages":"23-33"},"PeriodicalIF":0.0,"publicationDate":"2016-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557988","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 : 2016-07-29DOI: 10.12677/OJAV.2016.42002
甄亚欣
本文基于非局部弹性理论和欧拉梁理论，研究了磁场和温度场耦合作用下输流碳纳米管的动力学特性。采用微分求积法进行求解，详细讨论了常温环境下温度变化量和磁通量等对系统的振动频率和临界流速的影响。结果表明随着温度变化量的增大，系统的振动频率和临界流速都增大。随着磁通量的增大，系统的振动频率和临界流速明显增大，增强磁场能够显著提高系统的稳定性。 In this paper, based on nonlocal elasticity theory and Euler-Bernoulli beam theory, we investigate the dynamical characteristics of carbon nanotubes conveying fluid under longitudinal magnetic field with considering thermal effect. Differential quadrature method is used to do the simulation. The influence of temperature changes under normal atmospheric temperature and magnetic flux on the natural frequency and critical flow velocity are discussed in detail. The results show that the natural frequencies and critical flow velocity increase as the temperature changes increase. As the magnetic flux increases, the natural frequency and critical flow velocity increase distinctly, which demonstrate that increase the magnetic flux can obviously improve the stability of the fluid- conveying system.
本文基于非局部弹性理论和欧拉梁理论，研究了磁场和温度场耦合作用下输流碳纳米管的动力学特性。采用微分求积法进行求解，详细讨论了常温环境下温度变化量和磁通量等对系统的振动频率和临界流速的影响。结果表明随着温度变化量的增大，系统的振动频率和临界流速都增大。随着磁通量的增大，系统的振动频率和临界流速明显增大，增强磁场能够显著提高系统的稳定性。 In this paper, based on nonlocal elasticity theory and Euler-Bernoulli beam theory, we investigate the dynamical characteristics of carbon nanotubes conveying fluid under longitudinal magnetic field with considering thermal effect. Differential quadrature method is used to do the simulation. The influence of temperature changes under normal atmospheric temperature and magnetic flux on the natural frequency and critical flow velocity are discussed in detail. The results show that the natural frequencies and critical flow velocity increase as the temperature changes increase. As the magnetic flux increases, the natural frequency and critical flow velocity increase distinctly, which demonstrate that increase the magnetic flux can obviously improve the stability of the fluid- conveying system.
{"title":"磁场环境下输流碳纳米管的热振动与稳定性分析 Thermal-Mechanical Vibration and Stability Analysis of Fluid-Conveying Carbon Nanotubes under Magnetic Field","authors":"甄亚欣","doi":"10.12677/OJAV.2016.42002","DOIUrl":"https://doi.org/10.12677/OJAV.2016.42002","url":null,"abstract":"本文基于非局部弹性理论和欧拉梁理论，研究了磁场和温度场耦合作用下输流碳纳米管的动力学特性。采用微分求积法进行求解，详细讨论了常温环境下温度变化量和磁通量等对系统的振动频率和临界流速的影响。结果表明随着温度变化量的增大，系统的振动频率和临界流速都增大。随着磁通量的增大，系统的振动频率和临界流速明显增大，增强磁场能够显著提高系统的稳定性。 In this paper, based on nonlocal elasticity theory and Euler-Bernoulli beam theory, we investigate the dynamical characteristics of carbon nanotubes conveying fluid under longitudinal magnetic field with considering thermal effect. Differential quadrature method is used to do the simulation. The influence of temperature changes under normal atmospheric temperature and magnetic flux on the natural frequency and critical flow velocity are discussed in detail. The results show that the natural frequencies and critical flow velocity increase as the temperature changes increase. As the magnetic flux increases, the natural frequency and critical flow velocity increase distinctly, which demonstrate that increase the magnetic flux can obviously improve the stability of the fluid- conveying system.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"04 1","pages":"11-18"},"PeriodicalIF":0.0,"publicationDate":"2016-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177778","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}
There is a new method of calculating the trajectory of sound waves (rays) in layered stratified speed of sound in ocean without dispersion. A sound wave in the fluid is considered as a vector. The amplitudes occurring at the boundary layers of the reflected and refracted waves are calculated according to the law of addition of vectors and using the law of conservation of energy, as well as the laws that determine the angles of reflection and refraction. It is shown that in calculating the trajectories, the reflected wave must be taken into account. The reflecting wave’s value may be about 1 at certain angles of the initial wave output from the sours. Reflecting wave forms the so-called water rays, which do not touch the bottom and the surface of the ocean. The conditions of occurrence of the water rays are following. The sum of the angles of the incident and refracted waves (rays) should be a right angle, and the tangent of the angle of inclination of the incident wave is equal to the refractive index. Under these conditions, the refracted wave amplitude vanishes. All sound energy is converted into the reflected beam, and total internal reflection occurs. In this paper, the calculation of the amplitudes and beam trajectories is conducted for the canonical type of waveguide, in which the speed of sound is asymmetric parabola. The sound source is placed at the depth of the center of the parabola. Total internal reflection occurs in a narrow range of angles of exit beams from the source 43° - 45°. Within this range of angles, the water rays form and not touch the bottom and surface of ocean. Outside this range, the bulk of the beam spreads, touching the bottom and the surface of the ocean. When exit corners, equal and greater than 77°, at some distance the beam becomes horizontal and extends along the layer, without leaving it. Calculation of the wave amplitudes excludes absorption factor. Note that the formula for amplitudes of the sound waves applies to light waves.
{"title":"New Method in Calculating the Trajectory of Sound Waves at Stratified Ocean","authors":"V. Ivanov, G. K. Ivanova","doi":"10.4236/OJA.2016.62002","DOIUrl":"https://doi.org/10.4236/OJA.2016.62002","url":null,"abstract":"There is a new method of calculating the trajectory of sound waves (rays) in layered stratified speed of sound in ocean without dispersion. A sound wave in the fluid is considered as a vector. The amplitudes occurring at the boundary layers of the reflected and refracted waves are calculated according to the law of addition of vectors and using the law of conservation of energy, as well as the laws that determine the angles of reflection and refraction. It is shown that in calculating the trajectories, the reflected wave must be taken into account. The reflecting wave’s value may be about 1 at certain angles of the initial wave output from the sours. Reflecting wave forms the so-called water rays, which do not touch the bottom and the surface of the ocean. The conditions of occurrence of the water rays are following. The sum of the angles of the incident and refracted waves (rays) should be a right angle, and the tangent of the angle of inclination of the incident wave is equal to the refractive index. Under these conditions, the refracted wave amplitude vanishes. All sound energy is converted into the reflected beam, and total internal reflection occurs. In this paper, the calculation of the amplitudes and beam trajectories is conducted for the canonical type of waveguide, in which the speed of sound is asymmetric parabola. The sound source is placed at the depth of the center of the parabola. Total internal reflection occurs in a narrow range of angles of exit beams from the source 43° - 45°. Within this range of angles, the water rays form and not touch the bottom and surface of ocean. Outside this range, the bulk of the beam spreads, touching the bottom and the surface of the ocean. When exit corners, equal and greater than 77°, at some distance the beam becomes horizontal and extends along the layer, without leaving it. Calculation of the wave amplitudes excludes absorption factor. Note that the formula for amplitudes of the sound waves applies to light waves.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"261 1","pages":"13-21"},"PeriodicalIF":0.0,"publicationDate":"2016-07-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557952","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 : 2016-06-30DOI: 10.12677/OJAV.2016.41001
何远鹏, 韩健, 王开云, 圣小珍
钢弹簧浮置板轨道是地铁中常用的减振轨道结构之一，该种轨道结构利用螺旋钢弹簧把轨道结构与基础分开，使轨道板处于悬浮状态，将轨道板振动隔离。本文建立钢弹簧浮置板轨道板有限元模型与传统地铁无砟轨道有限元模型；在该模型中考虑了隧道以及大地的影响，同时使用粘弹性人工边界条件来模拟大地的无限长特性，在轮轨粗糙度激励下，对比分析了钢弹簧浮置板轨道结构和传统地铁无砟轨道结构的振动特性以及钢弹簧浮置板的减振效果。 Steel spring floating slab track is one of the common tracks of vibration reduction used in metro. The steel spring separates track structure and its foundation, which makes the slab instate of suspension to isolate vibration. In this paper, the finite element model of steel spring floating slab track and the traditional ballastless track of metro is established. In the model, the tunnel and ground are considered, and the visco-elasticartificial boundaries are used to simulate the infinite characteristic of the ground. In the excitation of wheel-rail roughness, the vibration characteristic of steel spring floating lab track is analyzed, and vibration reduction effect of steel spring floating slab track is compared to that of the traditional ballastless track of metro.
钢弹簧浮置板轨道是地铁中常用的减振轨道结构之一，该种轨道结构利用螺旋钢弹簧把轨道结构与基础分开，使轨道板处于悬浮状态，将轨道板振动隔离。本文建立钢弹簧浮置板轨道板有限元模型与传统地铁无砟轨道有限元模型；在该模型中考虑了隧道以及大地的影响，同时使用粘弹性人工边界条件来模拟大地的无限长特性，在轮轨粗糙度激励下，对比分析了钢弹簧浮置板轨道结构和传统地铁无砟轨道结构的振动特性以及钢弹簧浮置板的减振效果。 Steel spring floating slab track is one of the common tracks of vibration reduction used in metro. The steel spring separates track structure and its foundation, which makes the slab instate of suspension to isolate vibration. In this paper, the finite element model of steel spring floating slab track and the traditional ballastless track of metro is established. In the model, the tunnel and ground are considered, and the visco-elasticartificial boundaries are used to simulate the infinite characteristic of the ground. In the excitation of wheel-rail roughness, the vibration characteristic of steel spring floating lab track is analyzed, and vibration reduction effect of steel spring floating slab track is compared to that of the traditional ballastless track of metro.
{"title":"基于频域法的地铁钢弹簧浮置板轨道结构减振特性分析 The Vibration Reduction Characteristics of Steel Spring Floating Slab Track Used in Metro Based on Frequency-Domain Method","authors":"何远鹏, 韩健, 王开云, 圣小珍","doi":"10.12677/OJAV.2016.41001","DOIUrl":"https://doi.org/10.12677/OJAV.2016.41001","url":null,"abstract":"钢弹簧浮置板轨道是地铁中常用的减振轨道结构之一，该种轨道结构利用螺旋钢弹簧把轨道结构与基础分开，使轨道板处于悬浮状态，将轨道板振动隔离。本文建立钢弹簧浮置板轨道板有限元模型与传统地铁无砟轨道有限元模型；在该模型中考虑了隧道以及大地的影响，同时使用粘弹性人工边界条件来模拟大地的无限长特性，在轮轨粗糙度激励下，对比分析了钢弹簧浮置板轨道结构和传统地铁无砟轨道结构的振动特性以及钢弹簧浮置板的减振效果。 Steel spring floating slab track is one of the common tracks of vibration reduction used in metro. The steel spring separates track structure and its foundation, which makes the slab instate of suspension to isolate vibration. In this paper, the finite element model of steel spring floating slab track and the traditional ballastless track of metro is established. In the model, the tunnel and ground are considered, and the visco-elasticartificial boundaries are used to simulate the infinite characteristic of the ground. In the excitation of wheel-rail roughness, the vibration characteristic of steel spring floating lab track is analyzed, and vibration reduction effect of steel spring floating slab track is compared to that of the traditional ballastless track of metro.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"53 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2016-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177697","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}
A set of dolphin echolocation signals previously collected from an Atlantic bottlenose dolphin in Kaneohe Bay, Hawai’i are decomposed using a matching pursuit algorithm to further investigate the role of four types of echolocation signals outlined elsewhere [1]. The method decomposes the echolocation signals into optimal linear expansions of waveforms, which are Gabor functions defined in a dictionary. The method allows for study of the changes in frequency content within a dolphin’s functional bandwidth during discrimination tasks. We investigate the role of the functional bandwidth in terms of the signal energy levels and echolocations task performance. Furthermore, ROC analysis is applied to the relative energies of the matched waveforms to determine probability of discrimination. The results suggest that dolphins may discriminate by inspection of the relevant frequency differences between targets. In addition, the results from the ROC analysis provides insight into the role of the different classes of dolphin signals and of the importance of modification of the outgoing echolocation clicks, which may be fundamental to a dolphin’s ability to identify and discriminate targets.
{"title":"Frequency and Energy Difference Detection of Dolphin Biosonar Signals Using a Decomposition Algorithm","authors":"M. W. Muller","doi":"10.4236/OJA.2016.61001","DOIUrl":"https://doi.org/10.4236/OJA.2016.61001","url":null,"abstract":"A set of dolphin echolocation signals previously collected from an Atlantic bottlenose dolphin in Kaneohe Bay, Hawai’i are decomposed using a matching pursuit algorithm to further investigate the role of four types of echolocation signals outlined elsewhere [1]. The method decomposes the echolocation signals into optimal linear expansions of waveforms, which are Gabor functions defined in a dictionary. The method allows for study of the changes in frequency content within a dolphin’s functional bandwidth during discrimination tasks. We investigate the role of the functional bandwidth in terms of the signal energy levels and echolocations task performance. Furthermore, ROC analysis is applied to the relative energies of the matched waveforms to determine probability of discrimination. The results suggest that dolphins may discriminate by inspection of the relevant frequency differences between targets. In addition, the results from the ROC analysis provides insight into the role of the different classes of dolphin signals and of the importance of modification of the outgoing echolocation clicks, which may be fundamental to a dolphin’s ability to identify and discriminate targets.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"6 1","pages":"1-12"},"PeriodicalIF":0.0,"publicationDate":"2016-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70557937","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 : 2015-12-03DOI: 10.12677/OJAV.2015.34006
季同盛, 王涛, 周根明, 郭霆
本文中，我们采用试验方法对核级应急柴油发电机组进行抗震鉴定。使用连续白噪声方法，测得机组在三正交轴上的固有频率和阻尼比。根据业主提供的楼板反应谱，生成人工地震波，对机组三正交轴向同时输入模拟地震加速度时程进行激振，分别进行了5次OBE (运行基准地震)和1次SSE (安全停堆地震)地震模拟振动台试验，试验表明机组各项性能指标在抗震试验前后无明显变化，抗震性能满足要求。 In this paper, we do the seismic identification of nuclear emergency diesel generator by test method. Dynamic characteristics including orthogonal tri-axial fundamental frequencies and equivalent damping ratios were measured by using the white noise scanning method. Artificial seismic waves were generated according to the floor acceleration response spectrum provided by the owners. Furthermore, five OBE and one SSE shaking table tests for emergency diesel generator were done by using the artificial seismic waves as seismic inputs along the orthogonal tri-axial simultaneity. The results show that the emergency diesel generator satisfies the seismic requirements and there is no obvious change of its performances before and after the earthquake test.
本文中，我们采用试验方法对核级应急柴油发电机组进行抗震鉴定。使用连续白噪声方法，测得机组在三正交轴上的固有频率和阻尼比。根据业主提供的楼板反应谱，生成人工地震波，对机组三正交轴向同时输入模拟地震加速度时程进行激振，分别进行了5次OBE (运行基准地震)和1次SSE (安全停堆地震)地震模拟振动台试验，试验表明机组各项性能指标在抗震试验前后无明显变化，抗震性能满足要求。 In this paper, we do the seismic identification of nuclear emergency diesel generator by test method. Dynamic characteristics including orthogonal tri-axial fundamental frequencies and equivalent damping ratios were measured by using the white noise scanning method. Artificial seismic waves were generated according to the floor acceleration response spectrum provided by the owners. Furthermore, five OBE and one SSE shaking table tests for emergency diesel generator were done by using the artificial seismic waves as seismic inputs along the orthogonal tri-axial simultaneity. The results show that the emergency diesel generator satisfies the seismic requirements and there is no obvious change of its performances before and after the earthquake test.
{"title":"核级应急柴油发电机组抗震试验研究 A Study of Seismic Testing for Nuclear Emergency Diesel Generator","authors":"季同盛, 王涛, 周根明, 郭霆","doi":"10.12677/OJAV.2015.34006","DOIUrl":"https://doi.org/10.12677/OJAV.2015.34006","url":null,"abstract":"本文中，我们采用试验方法对核级应急柴油发电机组进行抗震鉴定。使用连续白噪声方法，测得机组在三正交轴上的固有频率和阻尼比。根据业主提供的楼板反应谱，生成人工地震波，对机组三正交轴向同时输入模拟地震加速度时程进行激振，分别进行了5次OBE (运行基准地震)和1次SSE (安全停堆地震)地震模拟振动台试验，试验表明机组各项性能指标在抗震试验前后无明显变化，抗震性能满足要求。 In this paper, we do the seismic identification of nuclear emergency diesel generator by test method. Dynamic characteristics including orthogonal tri-axial fundamental frequencies and equivalent damping ratios were measured by using the white noise scanning method. Artificial seismic waves were generated according to the floor acceleration response spectrum provided by the owners. Furthermore, five OBE and one SSE shaking table tests for emergency diesel generator were done by using the artificial seismic waves as seismic inputs along the orthogonal tri-axial simultaneity. The results show that the emergency diesel generator satisfies the seismic requirements and there is no obvious change of its performances before and after the earthquake test.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"03 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177364","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 : 2015-12-03DOI: 10.12677/OJAV.2015.34007
孙霖
以典型DN125通海阀为对象，在通海阀主要结构尺寸不变的情况下对其局部部位进行改进优化，分别提出了四种优化方案，并对优化方案的声学特性进行分析。分析结果表明，其中方案二和方案四的流体噪声声功率级均大幅下降，且工艺性良好。 By using a typical seacock for DN125 as the object, under the condition of invariable in the main structure size, we optimized the local area, put forward four kinds of optimization schemes re-spectively, and analyzed the acoustic characteristics of the optimized schemes. The results show that the sound power levels of fluid noise significantly decrease in the second and fourth schemes, and the manufacturability is feasible.
以典型DN125通海阀为对象，在通海阀主要结构尺寸不变的情况下对其局部部位进行改进优化，分别提出了四种优化方案，并对优化方案的声学特性进行分析。分析结果表明，其中方案二和方案四的流体噪声声功率级均大幅下降，且工艺性良好。 By using a typical seacock for DN125 as the object, under the condition of invariable in the main structure size, we optimized the local area, put forward four kinds of optimization schemes re-spectively, and analyzed the acoustic characteristics of the optimized schemes. The results show that the sound power levels of fluid noise significantly decrease in the second and fourth schemes, and the manufacturability is feasible.
{"title":"DN125低噪声通海阀结构初步设计及其声学特性分析 The Preliminary Design and Acoustic Characteristics Analysis of the Low Noise Seacock for DN125","authors":"孙霖","doi":"10.12677/OJAV.2015.34007","DOIUrl":"https://doi.org/10.12677/OJAV.2015.34007","url":null,"abstract":"以典型DN125通海阀为对象，在通海阀主要结构尺寸不变的情况下对其局部部位进行改进优化，分别提出了四种优化方案，并对优化方案的声学特性进行分析。分析结果表明，其中方案二和方案四的流体噪声声功率级均大幅下降，且工艺性良好。 By using a typical seacock for DN125 as the object, under the condition of invariable in the main structure size, we optimized the local area, put forward four kinds of optimization schemes re-spectively, and analyzed the acoustic characteristics of the optimized schemes. The results show that the sound power levels of fluid noise significantly decrease in the second and fourth schemes, and the manufacturability is feasible.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"03 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177605","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 : 2015-12-03DOI: 10.12677/OJAV.2015.34005
顾梦引, 李惠彬, 上官云飞
本文以某国产轻卡为研究对象，建立了其动力总成悬置系统六自由度振动力学模型。利用Matlab计算出其固有频率、主振型、能量分布矩阵和广义力传递率。以悬置系统的解耦及广义力传递率为优化目标，并对系统的固有频率范围及刚度参数上下限加以约束，用遗传算法对悬置刚度、安装位置同时进行了优化设计，使悬置系统在怠速工况下的隔振效果大大提高。 In this paper a six-degree freedom vibration mechanical model of the powertrain mounting system of a light truck made in China is set up. The natural frequency, principal mode, energy distribution matrix and generalized force transmissibility are counted by Matlab. We take decoupling and generalized force transmissibility of powertrain mounting systems as the optimization goals, restrict the natural frequency range and the limit of stiffness parameters, and have optimized the design of mounting stiffness parameters and mounting positions through genetic algorithm. As a result, the isolation effect of the powertrain mounting system at idle speed is greatly improved.
本文以某国产轻卡为研究对象，建立了其动力总成悬置系统六自由度振动力学模型。利用Matlab计算出其固有频率、主振型、能量分布矩阵和广义力传递率。以悬置系统的解耦及广义力传递率为优化目标，并对系统的固有频率范围及刚度参数上下限加以约束，用遗传算法对悬置刚度、安装位置同时进行了优化设计，使悬置系统在怠速工况下的隔振效果大大提高。 In this paper a six-degree freedom vibration mechanical model of the powertrain mounting system of a light truck made in China is set up. The natural frequency, principal mode, energy distribution matrix and generalized force transmissibility are counted by Matlab. We take decoupling and generalized force transmissibility of powertrain mounting systems as the optimization goals, restrict the natural frequency range and the limit of stiffness parameters, and have optimized the design of mounting stiffness parameters and mounting positions through genetic algorithm. As a result, the isolation effect of the powertrain mounting system at idle speed is greatly improved.
{"title":"基于解耦及广义力传递率的轻卡动力总成悬置刚度参数优化 Optimal Design of Powertrain Mounting Stiffness Parameters of Light Trucks for Decoupling Ratio and Generalized Force Transmissibility","authors":"顾梦引, 李惠彬, 上官云飞","doi":"10.12677/OJAV.2015.34005","DOIUrl":"https://doi.org/10.12677/OJAV.2015.34005","url":null,"abstract":"本文以某国产轻卡为研究对象，建立了其动力总成悬置系统六自由度振动力学模型。利用Matlab计算出其固有频率、主振型、能量分布矩阵和广义力传递率。以悬置系统的解耦及广义力传递率为优化目标，并对系统的固有频率范围及刚度参数上下限加以约束，用遗传算法对悬置刚度、安装位置同时进行了优化设计，使悬置系统在怠速工况下的隔振效果大大提高。 In this paper a six-degree freedom vibration mechanical model of the powertrain mounting system of a light truck made in China is set up. The natural frequency, principal mode, energy distribution matrix and generalized force transmissibility are counted by Matlab. We take decoupling and generalized force transmissibility of powertrain mounting systems as the optimization goals, restrict the natural frequency range and the limit of stiffness parameters, and have optimized the design of mounting stiffness parameters and mounting positions through genetic algorithm. As a result, the isolation effect of the powertrain mounting system at idle speed is greatly improved.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"03 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66177281","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 the present communication, the hydrodynamic model is used to investigate the amplitude modulation as well as demodulation of an electromagnetic wave of high power helicon pump wave into another helicon wave in strain dependent dielectric material incorporating carrier heating (CH) effects. The consideration of CH in modulation and demodulation is prime importance for the adding of new dimension in analysis of amplification of acoustic helicon wave. By using the dispersion relation, threshold pump electric filed and growth rate of unstable mode from the modulation and demodulation of the high power helicon wave well above from the threshold value will be discussed in the present analysis. The numerical analysis is applied to a strain dependent dielectric material, BaTiO3 at room temperature and irradiated with high power helicon wave of frequency 1.78 × 1014 Hz. This material is very sensitive to the pump intensities, therefore during studies, Gaussian shape of the helicon pump wave is considered during the propagation in stain dependent dielectric material and opto-acoustic wave in the form of Gaussian profile (ω0,κ0) is induced longitudinally along the crystallographic plane of BaTiO3. Its variation is caused by the available magnetic field (ωc), interaction length (z) and pulsed duration of interaction (τ). From the analysis of numerical results, the incorporation of CH effect can effectively modify the magnitude of modulation or demodulation of the amplitude of high power helicon laser wave through diffusion process. Not only the amplitude modulation and demodulation of the wave, the diffusion of the CH effectively modifies the growth rate of unstable mode of frequency in BaTiO3. The propagation of the threshold electric field shows the sinusoidal or complete Gaussian profile, whereas this profile is found to be completely lost in growth of unstable mode. It has also been seen that the growth rate is observed to be of the order of 108 - 1010 s-1 but from diffusion of carrier heating, and that its order is enhanced from 1010 - 1012 s-1 with the variation of the magnetized frequency from 1 to 2.5 × 1014 Hz.
{"title":"Effect of Hot Carrier on Amplitude Modulation and Demodulation of Gaussian High Power Helicon Wave in Homogeneous Longitudinally Magnetized Strain Dependent Dielectric Material","authors":"S. Saxena, S. Dixit, S. Srivastava","doi":"10.4236/OJA.2015.54012","DOIUrl":"https://doi.org/10.4236/OJA.2015.54012","url":null,"abstract":"In the present communication, the hydrodynamic model is used to investigate the amplitude modulation as well as demodulation of an electromagnetic wave of high power helicon pump wave into another helicon wave in strain dependent dielectric material incorporating carrier heating (CH) effects. The consideration of CH in modulation and demodulation is prime importance for the adding of new dimension in analysis of amplification of acoustic helicon wave. By using the dispersion relation, threshold pump electric filed and growth rate of unstable mode from the modulation and demodulation of the high power helicon wave well above from the threshold value will be discussed in the present analysis. The numerical analysis is applied to a strain dependent dielectric material, BaTiO3 at room temperature and irradiated with high power helicon wave of frequency 1.78 × 1014 Hz. This material is very sensitive to the pump intensities, therefore during studies, Gaussian shape of the helicon pump wave is considered during the propagation in stain dependent dielectric material and opto-acoustic wave in the form of Gaussian profile (ω0,κ0) is induced longitudinally along the crystallographic plane of BaTiO3. Its variation is caused by the available magnetic field (ωc), interaction length (z) and pulsed duration of interaction (τ). From the analysis of numerical results, the incorporation of CH effect can effectively modify the magnitude of modulation or demodulation of the amplitude of high power helicon laser wave through diffusion process. Not only the amplitude modulation and demodulation of the wave, the diffusion of the CH effectively modifies the growth rate of unstable mode of frequency in BaTiO3. The propagation of the threshold electric field shows the sinusoidal or complete Gaussian profile, whereas this profile is found to be completely lost in growth of unstable mode. It has also been seen that the growth rate is observed to be of the order of 108 - 1010 s-1 but from diffusion of carrier heating, and that its order is enhanced from 1010 - 1012 s-1 with the variation of the magnetized frequency from 1 to 2.5 × 1014 Hz.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"05 1","pages":"139-152"},"PeriodicalIF":0.0,"publicationDate":"2015-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70558027","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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