Pub Date : 2020-04-30DOI: 10.12677/ojav.2020.82009
俊灵 曹
{"title":"Balancing of Sliding Bearing Supported Rotor Based on Generative Adversarial Network","authors":"俊灵 曹","doi":"10.12677/ojav.2020.82009","DOIUrl":"https://doi.org/10.12677/ojav.2020.82009","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"66-76"},"PeriodicalIF":0.0,"publicationDate":"2020-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47319116","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}
Daliwa Joseph Bainamndi, Emmanuel Syriabe, S. Y. Doka, G. Ntamack
This paper addresses the effect of high temperature on absorption performance of sandwich material coupled with microperforated panels (MPPs) in multiple configurations using a finite element model (FEM) over a frequency range from 10 to 3000 Hz. The structure is backed with a rigid wall which can either be Aluminium or Al-Alloy used in aeronautic or automobile. The wave propagation in porous media is addressed using Johnson Champoux Allard model (JCA). The FEM model developed using COMSOL Multiphysics software makes it possible to predict the acoustic absorption coefficient in multilayer microperforated panels (M-MPPs) and sandwich structure. It is shown that, when structures made by MPPs or sandwich materials are submitted to high temperature, the absorption performance of the structure is strongly modified in terms of amplitude and width of the bandgap. For application in sever environment (noise reduction in engines aircrafts), Temperature is one of the parameters that will most influence the absorption performance of the structure. However, for application in the temperature domain smaller than 50?C (automotive applications for example), the effect of temperature is not significant on absorption performance of the structure.
{"title":"High Temperature Effect on Absorption Coefficient of M-MPPs and Sandwich Structures Coupled with MPPs","authors":"Daliwa Joseph Bainamndi, Emmanuel Syriabe, S. Y. Doka, G. Ntamack","doi":"10.4236/oja.2020.101001","DOIUrl":"https://doi.org/10.4236/oja.2020.101001","url":null,"abstract":"This paper addresses the effect of high temperature on absorption performance of sandwich material coupled with microperforated panels (MPPs) in multiple configurations using a finite element model (FEM) over a frequency range from 10 to 3000 Hz. The structure is backed with a rigid wall which can either be Aluminium or Al-Alloy used in aeronautic or automobile. The wave propagation in porous media is addressed using Johnson Champoux Allard model (JCA). The FEM model developed using COMSOL Multiphysics software makes it possible to predict the acoustic absorption coefficient in multilayer microperforated panels (M-MPPs) and sandwich structure. It is shown that, when structures made by MPPs or sandwich materials are submitted to high temperature, the absorption performance of the structure is strongly modified in terms of amplitude and width of the bandgap. For application in sever environment (noise reduction in engines aircrafts), Temperature is one of the parameters that will most influence the absorption performance of the structure. However, for application in the temperature domain smaller than 50?C (automotive applications for example), the effect of temperature is not significant on absorption performance of the structure.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44035984","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 : 2020-01-19DOI: 10.12677/ojav.2020.81002
姜仁威, 葛润发
{"title":"Comparative Study of Ship Vibration and Noise Reduction Performance","authors":"姜仁威, 葛润发","doi":"10.12677/ojav.2020.81002","DOIUrl":"https://doi.org/10.12677/ojav.2020.81002","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"9-16"},"PeriodicalIF":0.0,"publicationDate":"2020-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46260718","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 : 2020-01-01DOI: 10.12677/ojav.2020.81001
曹 俊灵
{"title":"PID Control of Quadrotor UAV Based on BP Neural Network","authors":"曹 俊灵","doi":"10.12677/ojav.2020.81001","DOIUrl":"https://doi.org/10.12677/ojav.2020.81001","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66179838","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 : 2020-01-01DOI: 10.12677/ojav.2020.82007
江涛 李
{"title":"Measurement and Analysis of Environmental Noise in Xiaoji Town, Xinxiang County, Henan Province","authors":"江涛 李","doi":"10.12677/ojav.2020.82007","DOIUrl":"https://doi.org/10.12677/ojav.2020.82007","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"49-56"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66179876","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 : 2020-01-01DOI: 10.12677/ojav.2020.81005
智祖 王
{"title":"Influence of Structural Design of Anechoic Tank on Sound Absorption Performance","authors":"智祖 王","doi":"10.12677/ojav.2020.81005","DOIUrl":"https://doi.org/10.12677/ojav.2020.81005","url":null,"abstract":"","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"08 1","pages":"33-38"},"PeriodicalIF":0.0,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66180244","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. C. Kiran, B. Mamatha, N. Anand, V. Prakash, N. Murthy
Coir fibre is extracted from the husk of coconut and is used in products such as floor mats, door mats, brushes and mattresses and in many applications. Here coir fibres are used to make particle boards of densities 300, 400 and 500 kg/m3 using UF resin to determine its efficiency for interior applications like acoustic and thermal properties and also tested for Indian standard 3129. Noise Reduction Coefficient (NRC) of all the boards decreases with an increase in density. Maximum sound absorption coefficient for all three densities was found in the frequency range of 2500 to 30,000 Hz. Among three densities, 300 kg/m3 board shows the maximum absorption coefficient at frequency 3000 Hz. The thermal conductivity results of all three densities boards increase with an increase in density. Modulus of Rupture for all three densities were meeting the requirement of standard. Results reveal that particle board manufactured from coir fibre can be used for acoustic and thermal insulation applications.
{"title":"Efficiency of Coir Particle Board for Acoustic & Thermal Applications","authors":"M. C. Kiran, B. Mamatha, N. Anand, V. Prakash, N. Murthy","doi":"10.4236/oja.2019.93004","DOIUrl":"https://doi.org/10.4236/oja.2019.93004","url":null,"abstract":"Coir fibre is extracted from the husk of coconut and is used in products such as floor mats, door mats, brushes and mattresses and in many applications. Here coir fibres are used to make particle boards of densities 300, 400 and 500 kg/m3 using UF resin to determine its efficiency for interior applications like acoustic and thermal properties and also tested for Indian standard 3129. Noise Reduction Coefficient (NRC) of all the boards decreases with an increase in density. Maximum sound absorption coefficient for all three densities was found in the frequency range of 2500 to 30,000 Hz. Among three densities, 300 kg/m3 board shows the maximum absorption coefficient at frequency 3000 Hz. The thermal conductivity results of all three densities boards increase with an increase in density. Modulus of Rupture for all three densities were meeting the requirement of standard. Results reveal that particle board manufactured from coir fibre can be used for acoustic and thermal insulation applications.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42955774","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}
It has been hypothesized that objective assessment for building acoustic conditions only may not always be representative of the users’ perception in occupied indoor spaces. This study objectively and subjectively examined indoor acoustic condition in rooms within students’ hostels in Obafemi Awolowo University, Nigeria. The objective assessment considered the physical measurement of sound pressure level in the rooms in relation to the rooms’ physical characteristics like window to external wall area and window to floor area ratios. The subjective assessment considered the occupants’ perception of the acoustic condition in the rooms in relation to their personal characteristics like age, gender, body mass index, metabolic rate, and body skin area. The sound pressure level was measured in each of the randomly selected 44 rooms at 15 minute intervals between 7 hours and 19 hours daily through a period of eight weeks. The measurement was done with High Accuracy Digital Sound Noise Level Data Loggers placed at work plane at the centre of the rooms. The geometry of the rooms was documented through physical measurements. All the occupants of the selected rooms as well as the two adjoining rooms, amounting to 696 respondents, were purposively selected to fill a questionnaire regarding activities carried out in the rooms, the frequency of fenestration opening, the personal characteristics of the occupants and the rooms’ occupancy ratio. This study established a strong correlation between the objective and subjective assessments of the acoustic condition in the spaces. Moreover, out of all the occupants’ personal characteristics considered, it was the age that has a relationship with the occupants’ perception of the acoustic condition that is closest to significant level.The relationship between their perception and measured sound pressure level was slightly more pronounced among the male gender than the female with correlation coefficients of 0.115 and 0.096 respectively. This study concluded that none of the considered occupants’ personal characteristics can effectively predict their response to indoor acoustic condition in the spaces.
{"title":"An Assessment of Indoor Acoustic Condition in Students Hostels within Obafemi Awolowo University, Nigeria","authors":"B. A. Orola, S. David","doi":"10.4236/OJA.2019.92002","DOIUrl":"https://doi.org/10.4236/OJA.2019.92002","url":null,"abstract":"It has been hypothesized that objective assessment for building acoustic conditions only may not always be representative of the users’ perception in occupied indoor spaces. This study objectively and subjectively examined indoor acoustic condition in rooms within students’ hostels in Obafemi Awolowo University, Nigeria. The objective assessment considered the physical measurement of sound pressure level in the rooms in relation to the rooms’ physical characteristics like window to external wall area and window to floor area ratios. The subjective assessment considered the occupants’ perception of the acoustic condition in the rooms in relation to their personal characteristics like age, gender, body mass index, metabolic rate, and body skin area. The sound pressure level was measured in each of the randomly selected 44 rooms at 15 minute intervals between 7 hours and 19 hours daily through a period of eight weeks. The measurement was done with High Accuracy Digital Sound Noise Level Data Loggers placed at work plane at the centre of the rooms. The geometry of the rooms was documented through physical measurements. All the occupants of the selected rooms as well as the two adjoining rooms, amounting to 696 respondents, were purposively selected to fill a questionnaire regarding activities carried out in the rooms, the frequency of fenestration opening, the personal characteristics of the occupants and the rooms’ occupancy ratio. This study established a strong correlation between the objective and subjective assessments of the acoustic condition in the spaces. Moreover, out of all the occupants’ personal characteristics considered, it was the age that has a relationship with the occupants’ perception of the acoustic condition that is closest to significant level.The relationship between their perception and measured sound pressure level was slightly more pronounced among the male gender than the female with correlation coefficients of 0.115 and 0.096 respectively. This study concluded that none of the considered occupants’ personal characteristics can effectively predict their response to indoor acoustic condition in the spaces.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42843493","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 study, noise pollution assessments were performed along Marechal Deodoro Avenue and Batel Avenue, which are two major thoroughfares in the city of Curitiba, Brazil. Eleven points were evaluated at Batel Avenue and 16 points at Marechal Deodoro Avenue. The results of the noise level measurements and the calculation of noise maps indicated that both thoroughfares are acoustically polluted. The simulated and measured noise levels, in the 27 evaluated points, exceed the limits established by law 10,625 of the city of Curitiba, which establishes acceptable levels for the comfort of the population in the external environment. With regard to the traffic composition in the areas under study, the vehicle flow was found to consist mostly of light vehicles, representing 88% of the total flow along Batel Avenue and 85% on Marshal Deodoro Street. Based on the noise maps and measured noise levels, it was found that the entire length of Marshal Deodoro Avenue and Batel Avenue are strongly affected by street noise, which is readily explained by the constant traffic, high vehicle flow (number of vehicles/hour) and high vehicle speed at some points of these thoroughfares.
{"title":"Assessment of Noise Pollution along Two Main Avenues in Curitiba, Brazil","authors":"P. Zannin, Felipe do Valle, E. Nascimento","doi":"10.4236/OJA.2019.92003","DOIUrl":"https://doi.org/10.4236/OJA.2019.92003","url":null,"abstract":"In this study, noise pollution assessments were performed along Marechal Deodoro Avenue and Batel Avenue, which are two major thoroughfares in the city of Curitiba, Brazil. Eleven points were evaluated at Batel Avenue and 16 points at Marechal Deodoro Avenue. The results of the noise level measurements and the calculation of noise maps indicated that both thoroughfares are acoustically polluted. The simulated and measured noise levels, in the 27 evaluated points, exceed the limits established by law 10,625 of the city of Curitiba, which establishes acceptable levels for the comfort of the population in the external environment. With regard to the traffic composition in the areas under study, the vehicle flow was found to consist mostly of light vehicles, representing 88% of the total flow along Batel Avenue and 85% on Marshal Deodoro Street. Based on the noise maps and measured noise levels, it was found that the entire length of Marshal Deodoro Avenue and Batel Avenue are strongly affected by street noise, which is readily explained by the constant traffic, high vehicle flow (number of vehicles/hour) and high vehicle speed at some points of these thoroughfares.","PeriodicalId":63563,"journal":{"name":"声学期刊(英文)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44693558","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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