Crypto-currency mining facilities have become more and more common over the last few years, but there is no standard for construction or noise mitigation for these facilities. Many noise issues are encountered after the facilities are complete and operating. The facilities can contain thousands of "miners" which can be quite loud. Often, the manufacturers do not supply reliable sound data and the miners themselves are constantly evolving. The miners have extreme power and ventilation requirements which introduce additional noise sources and paths, as well as site requirements. I have examined the effectiveness of mitigation techniques for these facilities and addressed potential pitfalls for facilities based on similar issues observed across several projects.
{"title":"Common pitfalls and potential solutions for crypto-currency mining facility noise","authors":"Iliana Schad","doi":"10.3397/nc_2023_0049","DOIUrl":"https://doi.org/10.3397/nc_2023_0049","url":null,"abstract":"Crypto-currency mining facilities have become more and more common over the last few years, but there is no standard for construction or noise mitigation for these facilities. Many noise issues are encountered after the facilities are complete and operating. The facilities can contain\u0000 thousands of \"miners\" which can be quite loud. Often, the manufacturers do not supply reliable sound data and the miners themselves are constantly evolving. The miners have extreme power and ventilation requirements which introduce additional noise sources and paths, as well as site\u0000 requirements. I have examined the effectiveness of mitigation techniques for these facilities and addressed potential pitfalls for facilities based on similar issues observed across several projects.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79988821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Alaska's Glacier Bay National Park preserves the seventh largest unit of the National Wilderness Preservation System, encompassing 2.6 million acres. Natural acoustic environments are significant to many of the unit's fundamental resources and values. Since 2001, the National Park Service has inventoried acoustic environments of Alaskan parks. One purpose is to document every noise-free interval (NFI) observed. NFI is defined as the time between human-generated noise disturbances. Aggregate properties of NFIs describe fragmentation of acoustic environments by noise. Median NFI estimated at parks in Alaska to date range from < 3 minutes to 16.7 hours, similar to other Arctic sites (0.5 to 13.0 hours, Stinchcomb et al. 2020). For the Glacier Bay Marine Management Plan Environmental Assessment, a geometric NFI model was developed using automatic identification system (AIS) derived vessel tracks. The NFI simulation results, along with NFI data from acoustic monitoring at the park, was then utilized to assess how changes to vessel quotas and vessel management strategies would potentially affect the NFI throughout the park. This paper will discuss the estimation and use of the NFI metric in protected natural areas, along with NFI modeling methods utilized for an environmental assessment at Glacier Bay.
阿拉斯加的冰川湾国家公园是国家荒野保护系统的第七大单位，占地260万英亩。自然声学环境对许多单位的基本资源和价值都很重要。自2001年以来，国家公园管理局对阿拉斯加公园的声环境进行了盘点。目的之一是记录观察到的每个无噪声间隔(NFI)。NFI定义为人为噪声干扰之间的时间间隔。NFIs的聚集特性描述了噪声对声环境的破坏。迄今为止，阿拉斯加公园估计的NFI中位数范围为< 3分钟至16.7小时，与其他北极地点相似(0.5至13.0小时，Stinchcomb et al. 2020)。在冰川湾海洋管理计划环境评估中，使用自动识别系统(AIS)衍生的船只轨迹开发了几何NFI模型。然后利用NFI模拟结果以及来自公园声学监测的NFI数据来评估船舶配额和船舶管理策略的变化如何潜在地影响整个公园的NFI。本文将讨论自然保护区NFI指标的估计和使用，以及冰川湾环境评估中使用的NFI建模方法。
{"title":"Use of the noise-free interval (NFI) metric to assess the disturbances of airborne vessel noise at Glacier Bay National Park","authors":"J. Poling, D. Betchkal","doi":"10.3397/nc_2023_0120","DOIUrl":"https://doi.org/10.3397/nc_2023_0120","url":null,"abstract":"Alaska's Glacier Bay National Park preserves the seventh largest unit of the National Wilderness Preservation System, encompassing 2.6 million acres. Natural acoustic environments are significant to many of the unit's fundamental resources and values. Since 2001, the National Park Service\u0000 has inventoried acoustic environments of Alaskan parks. One purpose is to document every noise-free interval (NFI) observed. NFI is defined as the time between human-generated noise disturbances. Aggregate properties of NFIs describe fragmentation of acoustic environments by noise. Median\u0000 NFI estimated at parks in Alaska to date range from < 3 minutes to 16.7 hours, similar to other Arctic sites (0.5 to 13.0 hours, Stinchcomb et al. 2020). For the Glacier Bay Marine Management Plan Environmental Assessment, a geometric NFI model was developed using automatic identification\u0000 system (AIS) derived vessel tracks. The NFI simulation results, along with NFI data from acoustic monitoring at the park, was then utilized to assess how changes to vessel quotas and vessel management strategies would potentially affect the NFI throughout the park. This paper will discuss\u0000 the estimation and use of the NFI metric in protected natural areas, along with NFI modeling methods utilized for an environmental assessment at Glacier Bay.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84601819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A measurement of one stock and three custom designed propellers was conducted with the United States Air Force Academy. The measurement consisted of a constant radius arc, and a radial array to examine acoustic attributes as a function of distance and angle. During the measurement activity the experimenters' observed that each propeller possessed different audio attributes that assisted in distinguishing the stock from any of the custom propellers. To adequately explore attributes beyond the propeller's A-weighted level as a function of thrust, a timbre and sound quality analysis were conducted. These auditory feature extraction methods were combined with a fractional octave analysis into a database for machine learning classification analysis. The new baseline propeller is distinguished by the acoustic roughness alone, but the other blade designs require additional timbre features to be segregated from the stock propeller.
{"title":"Classification of SUAS propellers with auditory feature extraction methods","authors":"Frank S. Mobley","doi":"10.3397/nc_2023_0014","DOIUrl":"https://doi.org/10.3397/nc_2023_0014","url":null,"abstract":"A measurement of one stock and three custom designed propellers was conducted with the United States Air Force Academy. The measurement consisted of a constant radius arc, and a radial array to examine acoustic attributes as a function of distance and angle. During the measurement activity\u0000 the experimenters' observed that each propeller possessed different audio attributes that assisted in distinguishing the stock from any of the custom propellers. To adequately explore attributes beyond the propeller's A-weighted level as a function of thrust, a timbre and sound quality analysis\u0000 were conducted. These auditory feature extraction methods were combined with a fractional octave analysis into a database for machine learning classification analysis. The new baseline propeller is distinguished by the acoustic roughness alone, but the other blade designs require additional\u0000 timbre features to be segregated from the stock propeller.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78770913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pelumi Abiodun, O. Owolabi, Adebayo Olude, Petronella James-Okeke
Noise engineering is not a new field of study but statistics showed that experts in the field are on a decline. Observing that motivation and curiosity are among the hallmarks of any workforce development pipeline, the study developed an experiment-centric pedagogy to detect and measure noise from pollution using low-cost hands-on devices with the aim of motivating learners. The study design was a pre- and post-test method. The learners were enrolled in a transportation course and the noise detection and measurement strategies course module was used for the study. Motivated Strategies Learning Questionnaire was adopted for the study. Learners response to the use of technological tools incorporated in learning was predominantly positive revealing that the learners' gain extensively. More so, significant improvement was observed in the critical thinking of leaners (p < 0 .05) and overall, there was an increase in their motivation at the post-test. Significant improvement in academic performance of learners was also observed at post-test (p < 0 .05). It is therefore posited that there is need for effective engagement with learners with similar low-cost hands-on to lead to better understand and motivation that can lead to development of workforce in noise engineering.
{"title":"The impact of teaching noise detection and control strategies among historically black college and university student using hands-on pedagogy on student's motivation and curiosity","authors":"Pelumi Abiodun, O. Owolabi, Adebayo Olude, Petronella James-Okeke","doi":"10.3397/nc_2023_0182","DOIUrl":"https://doi.org/10.3397/nc_2023_0182","url":null,"abstract":"Noise engineering is not a new field of study but statistics showed that experts in the field are on a decline. Observing that motivation and curiosity are among the hallmarks of any workforce development pipeline, the study developed an experiment-centric pedagogy to detect and measure\u0000 noise from pollution using low-cost hands-on devices with the aim of motivating learners. The study design was a pre- and post-test method. The learners were enrolled in a transportation course and the noise detection and measurement strategies course module was used for the study. Motivated\u0000 Strategies Learning Questionnaire was adopted for the study. Learners response to the use of technological tools incorporated in learning was predominantly positive revealing that the learners' gain extensively. More so, significant improvement was observed in the critical thinking of leaners\u0000 (p < 0 .05) and overall, there was an increase in their motivation at the post-test. Significant improvement in academic performance of learners was also observed at post-test (p < 0 .05). It is therefore posited that there is need for effective engagement with learners with similar\u0000 low-cost hands-on to lead to better understand and motivation that can lead to development of workforce in noise engineering.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77185317","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hyun-Woo Han, Minwoo Kang, Seung-Je Cho, Young-Jun Park
Agricultural tractors are special purpose machines that perform agricultural operation in harsh environments such as unpaved roads and farmlands, and generate high levels of noise and vibration. Eco-friendly tractors using electric drivetrains and hydrogen fuel cells are being developed to reduce exhaust gas in accordance with global environmental regulations. Unlike traditional tractor structures, these electrified tractors are being developed as modular and shared platforms. Therefore, it is changing into a system that is easy to apply component-based transfer path analysis (C-TPA) to reduce noise and vibration of tractors. In this paper, the noise and vibration contributions of an agricultural tractor were analyzed using C-TPA, and the blocked force usable as the excitation force of the virtual model was derived. The accuracy of transfer path analysis was improved by applying transfer functions including the rotational directions using virtual point transformation technique. The prediction result of developed experimental model were similar to the vibration response of the actual tractor, and the contribution of structure-borne noise could be quantitatively evaluated.
{"title":"Component-based transfer path analysis on agricultural tractor","authors":"Hyun-Woo Han, Minwoo Kang, Seung-Je Cho, Young-Jun Park","doi":"10.3397/nc_2023_0177","DOIUrl":"https://doi.org/10.3397/nc_2023_0177","url":null,"abstract":"Agricultural tractors are special purpose machines that perform agricultural operation in harsh environments such as unpaved roads and farmlands, and generate high levels of noise and vibration. Eco-friendly tractors using electric drivetrains and hydrogen fuel cells are being developed\u0000 to reduce exhaust gas in accordance with global environmental regulations. Unlike traditional tractor structures, these electrified tractors are being developed as modular and shared platforms. Therefore, it is changing into a system that is easy to apply component-based transfer path analysis\u0000 (C-TPA) to reduce noise and vibration of tractors. In this paper, the noise and vibration contributions of an agricultural tractor were analyzed using C-TPA, and the blocked force usable as the excitation force of the virtual model was derived. The accuracy of transfer path analysis was improved\u0000 by applying transfer functions including the rotational directions using virtual point transformation technique. The prediction result of developed experimental model were similar to the vibration response of the actual tractor, and the contribution of structure-borne noise could be quantitatively\u0000 evaluated.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88785172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The success of new conceptual frameworks, which center the needs and expectations of occupants in the built environment, is predicated on the development of guiding principles describing the interactions and integration of different acoustical solutions. By way of example, speech privacy is the assessment of the degree of unintelligibility of speech between a talker and a listener. The evaluation is an equal function of the difference in level of the signal between the source and receiver locations, and the ambient acoustic conditions at the receiver. While there is ample literature describing strategies for employing acoustical solutions to mitigate the transmission of sound and absorb excess acoustic energy, there are few, if any, that offer guidance as to the interference of noise (emitted from critical building systems) on masking sound (emitted from a sound masking system) measurement. The proposed conceptual framework relies on acoustical theory to derive new mathematical relationships for effective implementation of sound masking systems. The conditions can enable optimization of the complex relationships implicating building-related systems' performance and efficiencies, speech privacy and acoustical comfort.
{"title":"Occupant-centric acoustical frameworks: Guiding principles to manage background sound","authors":"Viken N. Koukounian, N. Moeller","doi":"10.3397/nc_2023_0083","DOIUrl":"https://doi.org/10.3397/nc_2023_0083","url":null,"abstract":"The success of new conceptual frameworks, which center the needs and expectations of occupants in the built environment, is predicated on the development of guiding principles describing the interactions and integration of different acoustical solutions. By way of example, speech privacy\u0000 is the assessment of the degree of unintelligibility of speech between a talker and a listener. The evaluation is an equal function of the difference in level of the signal between the source and receiver locations, and the ambient acoustic conditions at the receiver. While there is ample\u0000 literature describing strategies for employing acoustical solutions to mitigate the transmission of sound and absorb excess acoustic energy, there are few, if any, that offer guidance as to the interference of noise (emitted from critical building systems) on masking sound (emitted from a\u0000 sound masking system) measurement. The proposed conceptual framework relies on acoustical theory to derive new mathematical relationships for effective implementation of sound masking systems. The conditions can enable optimization of the complex relationships implicating building-related\u0000 systems' performance and efficiencies, speech privacy and acoustical comfort.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84999114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Combined Heat and Power (CHP) plants have gained popularity in industrial and institutional applications due to their ability to recapture and repurpose wasted heat energy from the power generation process, resulting in significant energy savings and carbon emission reductions. However, noise control considerations have become increasingly critical in retrofit CHP systems, particularly in healthcare facilities. Often, strict noise performance requirements must be met due to the proximity of residential communities and to ensure a comfortable healing environment for patients.This technical paper explores critical noise control considerations for retrofit CHP systems in healthcare facilities, focusing on a case study from Hamilton Health Sciences, a healthcare network in Ontario, Canada. The paper examines the design challenges of upgrading the existing CHP plants across three separate hospitals when addressing stringent sound performance, system ventilation, air tempering, and structural capacity limitations within a limited space. The paper also discusses the unique sound attenuation design solutions implemented to address these challenges.The case study demonstrates the successful implementation of combining noise control design, ventilation design, and structural design into one integrated solution, specifically to overcome common design challenges in retrofit CHP systems.
{"title":"Considerations for noise control design in retrofit Combined Heat and Power Plants for Healthcare Facilities","authors":"Laura Fennema, Gregg W. Downey, M. Downey","doi":"10.3397/nc_2023_0069","DOIUrl":"https://doi.org/10.3397/nc_2023_0069","url":null,"abstract":"Combined Heat and Power (CHP) plants have gained popularity in industrial and institutional applications due to their ability to recapture and repurpose wasted heat energy from the power generation process, resulting in significant energy savings and carbon emission reductions. However,\u0000 noise control considerations have become increasingly critical in retrofit CHP systems, particularly in healthcare facilities. Often, strict noise performance requirements must be met due to the proximity of residential communities and to ensure a comfortable healing environment for patients.This\u0000 technical paper explores critical noise control considerations for retrofit CHP systems in healthcare facilities, focusing on a case study from Hamilton Health Sciences, a healthcare network in Ontario, Canada. The paper examines the design challenges of upgrading the existing CHP plants across\u0000 three separate hospitals when addressing stringent sound performance, system ventilation, air tempering, and structural capacity limitations within a limited space. The paper also discusses the unique sound attenuation design solutions implemented to address these challenges.The case study\u0000 demonstrates the successful implementation of combining noise control design, ventilation design, and structural design into one integrated solution, specifically to overcome common design challenges in retrofit CHP systems.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82737945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper summarizes various methodologies that were employed to determine design guidelines for improving the perceived sound quality of food blender appliances. These included designing, preparing sounds for, carrying out, and analyzing results from a consumer jury study, where the goal was to evaluate sound quality as determined by actual users, and to measure the impact and value of various possible modification scenarios. This jury study was configured to identify and quantify how various components and mechanisms operating within two types of blenders - a full size "pitcher-type" model, and a smaller "single-serve" model - affect user perceptions of sound quality, as expressed in terms of numerical ratings for two subjective attributes ("Acceptability" and "Overall Impression"), obtained by the jury listening to the sounds of various "virtual" blenders. Using regression models developed from the jury study results, it was then possible to identify several candidate modified designs for improving the attribute ratings, all by a similar degree.
{"title":"Sound quality studies as a tool for improving the sound of blenders","authors":"David J. Bowen","doi":"10.3397/nc_2023_0031","DOIUrl":"https://doi.org/10.3397/nc_2023_0031","url":null,"abstract":"This paper summarizes various methodologies that were employed to determine design guidelines for improving the perceived sound quality of food blender appliances. These included designing, preparing sounds for, carrying out, and analyzing results from a consumer jury study, where the\u0000 goal was to evaluate sound quality as determined by actual users, and to measure the impact and value of various possible modification scenarios. This jury study was configured to identify and quantify how various components and mechanisms operating within two types of blenders - a full size\u0000 \"pitcher-type\" model, and a smaller \"single-serve\" model - affect user perceptions of sound quality, as expressed in terms of numerical ratings for two subjective attributes (\"Acceptability\" and \"Overall Impression\"), obtained by the jury listening\u0000 to the sounds of various \"virtual\" blenders. Using regression models developed from the jury study results, it was then possible to identify several candidate modified designs for improving the attribute ratings, all by a similar degree.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89366190","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noise measurements were conducted of play during tennis and pickleball matches for the purposes of comparison and analysis. Modeling was conducted using a 3-D predictive noise modeling software package, and potential noise reduction measures in the form of absorptive noise barriers were modeled in order to assess the potential benefits at an adjacent residence. The paper presents the results of the analysis.
{"title":"Case study: measurements and modeling of noise from pickleball versus tennis play, and estimation of proposed noise reduction measures","authors":"Mike Greene, Jonathan Leech, Connor Burke","doi":"10.3397/nc_2023_0117","DOIUrl":"https://doi.org/10.3397/nc_2023_0117","url":null,"abstract":"Noise measurements were conducted of play during tennis and pickleball matches for the purposes of comparison and analysis. Modeling was conducted using a 3-D predictive noise modeling software package, and potential noise reduction measures in the form of absorptive noise barriers\u0000 were modeled in order to assess the potential benefits at an adjacent residence. The paper presents the results of the analysis.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86245101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Combustion oscillation is a very common phenomena in many unsteady or transient HVAC applications (e.g., start-up operation). Combustion driven oscillations can occur once the sound (thermo-acoustically driven) is reflected from the combustion chamber back into the mixture supply region (and propagate even further upstream). The reflected sound causes a fluctuation in inlet mixture composition or mixture flow. In either cases, the equivalence ratio is changed and consequently the amount of heat release changes. This phenomenon could easily trap the combustion process in a loop that can easily result in combustion oscillations with higher amplitude. It can also produce unwanted transient noise tones and can raise NOx emission levels. The current work is aimed at providing a simulation model for diagnosing and preventing combustion driven oscillation using a modified positive feedback loop. This feedback loop is developed using upstream/downstream impedances (obtained from low-order acoustic simulations), and a flame transfer function. The value-add of this study (model-based approach) is that it can help design engineers to reduce the number of test iterations and optimize the design.
{"title":"Prediction Of Combustion Driven Oscillation In A Residential Ultra-Low NOx Gas Furnace Product Using A Positive Feedback Stability Model","authors":"Ali Nikparto, Asad M. Sardar, D. Herrin","doi":"10.3397/nc_2023_0043","DOIUrl":"https://doi.org/10.3397/nc_2023_0043","url":null,"abstract":"Combustion oscillation is a very common phenomena in many unsteady or transient HVAC applications (e.g., start-up operation). Combustion driven oscillations can occur once the sound (thermo-acoustically driven) is reflected from the combustion chamber back into the mixture supply region\u0000 (and propagate even further upstream). The reflected sound causes a fluctuation in inlet mixture composition or mixture flow. In either cases, the equivalence ratio is changed and consequently the amount of heat release changes. This phenomenon could easily trap the combustion process in a\u0000 loop that can easily result in combustion oscillations with higher amplitude. It can also produce unwanted transient noise tones and can raise NOx emission levels. The current work is aimed at providing a simulation model for diagnosing and preventing combustion driven oscillation using a\u0000 modified positive feedback loop. This feedback loop is developed using upstream/downstream impedances (obtained from low-order acoustic simulations), and a flame transfer function. The value-add of this study (model-based approach) is that it can help design engineers to reduce the number\u0000 of test iterations and optimize the design.","PeriodicalId":19195,"journal":{"name":"Noise & Health","volume":null,"pages":null},"PeriodicalIF":0.7,"publicationDate":"2023-05-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80508455","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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