声学期刊(英文) Pub Date : 2021-06-18 DOI: 10.4236/oja.2021.112002

Massaï Hatoumva, E. Siryabe, P. Maréchal, G. Ntamack, G. Betchewe

{"title":"On the Simulation of the Influence of Defects on Immersed Plane Periodic Multilayer Viscoelastic Media","authors":"Massaï Hatoumva, E. Siryabe, P. Maréchal, G. Ntamack, G. Betchewe","doi":"10.4236/oja.2021.112002","DOIUrl":"https://doi.org/10.4236/oja.2021.112002","url":null,"abstract":"This work deals with the study of a plane periodic multilayer structure in which the elementary stack consists of two plates in contact: one in aluminum (AL) and the other one in polyethylene (PE). These isotropic materials, present a high acoustic impedance contrast. The attenuation of the longitudinal and transverse waves is taken into account in the polyethylene but neglected in the aluminum plate. The effect of different defects is analyzed. Firstly, we focus on the effect of the presence of grease inclusion in the polyethylene plate (considering the two plates of the elementary stack in perfect contact). Secondly, the effect of disbond simulated by the insertion of a thin Teflon layer between the interfaces of the two layers constituting the elementary stack of the multilayer structure is investigated. Finally, the effect of the stacking sequences of the multilayer is analyzed. In order to obtain the effective acoustic parameters of polyethylene layer, allowing to evaluate the reflection and transmission coefficients using the stiffness matrix method developed by Rokhlin et al., four homogenization models are analyzed, then the best one to our configuration is chosen. The comparison of the simulation results is carried out.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47685106","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}

引用次数: 0

CFD Simulation of Air Flow Behaviour at Different Flow Rates in a Turkish Woodwind Instrument (Turkish Treble Recorder) 土耳其木管乐器(土耳其高音记录器)不同流速下气流特性的CFD模拟

声学期刊(英文) Pub Date : 2021-03-28 DOI: 10.4236/OJA.2021.111001

H. K. Celik, Ali Bedel, S. Gok, A. Rennie

{"title":"CFD Simulation of Air Flow Behaviour at Different Flow Rates in a Turkish Woodwind Instrument (Turkish Treble Recorder)","authors":"H. K. Celik, Ali Bedel, S. Gok, A. Rennie","doi":"10.4236/OJA.2021.111001","DOIUrl":"https://doi.org/10.4236/OJA.2021.111001","url":null,"abstract":"In musical instruments, the geometric design and material features of the instrument are the most important factors that determine the sound characteristics of the instrument. Traditional replication and experiment-based handcrafting methods are predominant in the production of Turkish Folk Music wind instruments. The instrument manufacturing and standardization approaches, which include the relevant rules of physics and engineering practices, are limited purely to prototype studies for scientific research purposes. It is almost impossible to find studies on Turkish Folk Music wind instrument design and production involving computer aided design and engineering applications. In this study, an example Turkish woodwind instrument, the Turkish Treble Recorder (dilli kaval) is considered, and the air flow behaviour and acoustic (sound) power magnitudes that occur at different air flow rates are simulated in a computer environment using a Computational Fluid Dynamics (CFD) simulation technique. In the study, numerical and visual outputs related to air behaviour at different air flow rates that may be used in the instrument manufacturing phases were obtained. Acoustic power level was also measured experimentally. Simulation outputs (the acoustic power level) were compared to experimental results in order to validate the simulation results. The comparison revealed that the highest relative difference was calculated as 13.32(%). This value indicated that the simulation results were reasonably consistent with the results of the experimental measurement. Additionally, this study was constructed as a case study that may provide reference for future research studies in this field.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43786863","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}

引用次数: 1

Design and Analysis of Sandwich Structure with Negative Poisson’s Ratio for Vibration Reduction in Low Frequency Range 负泊松比夹层结构低频减振设计与分析

声学期刊(英文) Pub Date : 2021-01-01 DOI: 10.12677/OJAV.2021.91002

兆龙张

引用次数: 0

A Study on the Noise Characteristics of a Gasoline Vehicle under Typical Operating Conditions 典型工况下汽油车噪声特性研究

声学期刊(英文) Pub Date : 2021-01-01 DOI: 10.12677/OJAV.2021.91001

旭伟李

引用次数: 0

Vibration Simulation Analysis of Ceramic Matrix Composite Turbine Rotor Integral Blade-Disk 陶瓷基复合材料涡轮转子整体叶盘振动仿真分析

声学期刊(英文) Pub Date : 2021-01-01 DOI: 10.12677/OJAV.2021.91006

佳辉汪