Previous work has shown that active noise control (ANC) can be applied to axial cooling fans. Optimization of the control source and error sensor placement is desired to maximize the attenuation using ANC. A genetic algorithm was developed to find the optimal placement of control sources for a given primary source. The optimal configuration of control sources around a single primary source was shown to be a linear arrangement of the sources. This holds true for both two-dimensional as well as three-dimensional configurations. The higher-order radiation of the linear arrangement has also been verified experimentally, but the improvement in the experimental apparatus was not as dramatic as the theoretical model. Multiple flow visualization techniques have been used to find optimal near field error sensor locations. When there is little obstruction to the flow field of the fan, minimal airflow is found along the near field null that is created by minimizing the sound power of the system. Surface mounting of the error sensors can lead to a small increase in the signal-to-noise ratio of the error sensors if vortices exist in the near field of the fan due to obstructions in the main flow. It has also been shown that the introduction of the ANC system does not affect the flow field of the fan.
","abstract_html":"<p>Previous work has shown that active noise control (ANC) can be applied to axial cooling fans. Optimization of the control source and error sensor placement is desired to maximize the attenuation using ANC. A genetic algorithm was developed to find the optimal placement of control sources for a given primary source. The optimal configuration of control sources around a single primary source was shown to be a linear arrangement of the sources. This holds true for both two-dimensional as well as three-dimensional configurations. The higher-order radiation of the linear arrangement has also been verified experimentally, but the improvement in the experimental apparatus was not as dramatic as the theoretical model. Multiple flow visualization techniques have been used to find optimal near field error sensor locations. When there is little obstruction to the flow field of the fan, minimal airflow is found along the near field null that is created by minimizing the sound power of the system. Surface mounting of the error sensors can lead to a small increase in the signal-to-noise ratio of the error sensors if vortices exist in the near field of the fan due to obstructions in the main flow. It has also been shown that the introduction of the ANC system does not affect the flow field of the fan.</p>","abstract_has_math":false,"creators":["Duke, Connor Raymond"],"institution":"Brigham Young University - Provo","degree_name":"MS","degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T01:28:54Z","subjects":["Active Noise Control","Genetic algorithm","Free Field","Optimization","Parthenogenesis","Control Source","Error Sensor","Astrophysics and Astronomy","Physics"],"languages":["English"],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarsarchive.byu.edu/etd/1169","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Duke, Connor Raymond"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2007-08-28T07:00:00Z"]},{"key":"dc:publisher","label":"Institution","values":["Brigham Young University - Provo"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["MS"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Active Noise Control","Genetic algorithm","Free Field","Optimization","Parthenogenesis","Control Source","Error Sensor","Astrophysics and Astronomy","Physics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["English"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarsarchive.byu.edu/etd/1169","https://scholarsarchive.byu.edu/context/etd/article/2168/viewcontent/ETD_CISOPTR_1173.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Physical and Mathematical Sciences; Physics and Astronomy"]},{"key":"dc:description.abstract","label":"Abstract","values":["Previous work has shown that active noise control (ANC) can be applied to axial cooling fans. Optimization of the control source and error sensor placement is desired to maximize the attenuation using ANC. A genetic algorithm was developed to find the optimal placement of control sources for a given primary source. The optimal configuration of control sources around a single primary source was shown to be a linear arrangement of the sources. This holds true for both two-dimensional as well as three-dimensional configurations. The higher-order radiation of the linear arrangement has also been verified experimentally, but the improvement in the experimental apparatus was not as dramatic as the theoretical model. Multiple flow visualization techniques have been used to find optimal near field error sensor locations. When there is little obstruction to the flow field of the fan, minimal airflow is found along the near field null that is created by minimizing the sound power of the system. Surface mounting of the error sensors can lead to a small increase in the signal-to-noise ratio of the error sensors if vortices exist in the near field of the fan due to obstructions in the main flow. It has also been shown that the introduction of the ANC system does not affect the flow field of the fan.
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"],"dc:format":["application:pdf"],"dc:identifier":["https://scholarsarchive.byu.edu/etd/1169","https://scholarsarchive.byu.edu/context/etd/article/2168/viewcontent/ETD_CISOPTR_1173.pdf"],"dc:language":["English"],"dc:publisher":["Brigham Young University - Provo"],"dc:source":["Brigham Young University - Provo"],"dc:subject":["Active Noise Control","Genetic algorithm","Free Field","Optimization","Parthenogenesis","Control Source","Error Sensor","Astrophysics and Astronomy","Physics"],"dc:title":["Optimization of Control Source and Error Sensor Locations in Free Field Active Noise Control"],"dc:type":["Thesis"],"thesis:degree_name":["MS"]},"updated_at":"2026-07-24T01:28:54Z"}