東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

Fan Noise Attenuation with an Acoust...

Hill, Ryan.

FindBook

Google Book

Amazon

博客來

Fan Noise Attenuation with an Acoustic Metamaterial.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Fan Noise Attenuation with an Acoustic Metamaterial./
作者:	Hill, Ryan.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
面頁冊數:	101 p.
附註:	Source: Masters Abstracts International, Volume: 82-11.
Contained By:	Masters Abstracts International82-11.
標題:	Acoustics. -
電子資源:	https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28496958
ISBN:	9798738635342

Fan Noise Attenuation with an Acoustic Metamaterial.
Hill, Ryan.

Fan Noise Attenuation with an Acoustic Metamaterial. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 101 p.

Source: Masters Abstracts International, Volume: 82-11.

Thesis (M.S.)--The University of North Carolina at Charlotte, 2021.

This item must not be sold to any third party vendors.

In a world continuously increasing in the number of electronic devices, the need for cooling fans increases and so does its contribution to noise pollution. This project explores a solution to this problem by designing an acoustic metamaterial that attenuates the fan noise from a Sofasco fan, whose fundamental blade pass frequencyis approximately 800 Hz. According to Ping, two Helmholtz resonators (HRs) that are parallel side branched to a waveguide whose distance is less than a wavelength will have a hybrid resonance at the difference average. This approach did not work with the first generation samples, but the use of two parallel HRs was used in future designs. According to Sang-Hyun, the attenuation increases logarithmically for each parallel HR side branched to a waveguide. Using Sang-Hyun method, a second generation sample was designed that achieved a transmission loss of 45 dB, but it had an airflow loss of 75%. Other second generation designs explored decreasing the airflow loss, but none of the methods were successful. The third generation design has a waveguide shaped as a truncated sector, which increases the cross-sectional area of the waveguide as well as the airflow. The best sample of the third generation design had a transmission loss of 30 dB with an airflow loss of 45%. In an attempt to further decrease the airflow loss, the fourth generation design placed two HRs connected in series with each other (dual HRs) a side branch to the waveguide. The airflow loss was reduced to less than 1% with transmission loss of approximately 18 dB at 496 Hz and 1250 Hz. This design also led to a transmission loss of approximately 8 dB from 582 Hz to 1000 Hz. This design was never modified to achieve the fan frequency of800 Hz, but this can be achieved using design equations for dual HRs.

ISBN: 9798738635342Subjects--Topical Terms:

879105
Acoustics.
Subjects--Index Terms:

Fan noise

Fan Noise Attenuation with an Acoustic Metamaterial.
LDR:02878nmm a2200349 4500 001 2282248
005 20211001100735.5
008 220723s2021 ||||||||||||||||| ||eng d
020 $a 9798738635342
035 $a (MiAaPQ)AAI28496958
035 $a AAI28496958
040 $a MiAaPQ $c MiAaPQ
100 1 $a Hill, Ryan. $3 3561019
245 1 0 $a Fan Noise Attenuation with an Acoustic Metamaterial.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2021
300 $a 101 p.
500 $a Source: Masters Abstracts International, Volume: 82-11.
500 $a Advisor: Stokes, Ed.
502 $a Thesis (M.S.)--The University of North Carolina at Charlotte, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a In a world continuously increasing in the number of electronic devices, the need for cooling fans increases and so does its contribution to noise pollution. This project explores a solution to this problem by designing an acoustic metamaterial that attenuates the fan noise from a Sofasco fan, whose fundamental blade pass frequencyis approximately 800 Hz. According to Ping, two Helmholtz resonators (HRs) that are parallel side branched to a waveguide whose distance is less than a wavelength will have a hybrid resonance at the difference average. This approach did not work with the first generation samples, but the use of two parallel HRs was used in future designs. According to Sang-Hyun, the attenuation increases logarithmically for each parallel HR side branched to a waveguide. Using Sang-Hyun method, a second generation sample was designed that achieved a transmission loss of 45 dB, but it had an airflow loss of 75%. Other second generation designs explored decreasing the airflow loss, but none of the methods were successful. The third generation design has a waveguide shaped as a truncated sector, which increases the cross-sectional area of the waveguide as well as the airflow. The best sample of the third generation design had a transmission loss of 30 dB with an airflow loss of 45%. In an attempt to further decrease the airflow loss, the fourth generation design placed two HRs connected in series with each other (dual HRs) a side branch to the waveguide. The airflow loss was reduced to less than 1% with transmission loss of approximately 18 dB at 496 Hz and 1250 Hz. This design also led to a transmission loss of approximately 8 dB from 582 Hz to 1000 Hz. This design was never modified to achieve the fan frequency of800 Hz, but this can be achieved using design equations for dual HRs.
590 $a School code: 0694.
650 4 $a Acoustics. $3 879105
650 4 $a Electrical engineering. $3 649834
650 4 $a Materials science. $3 543314
653 $a Fan noise
653 $a Attenuation
653 $a Acoustic metamaterial
690 $a 0986
690 $a 0544
690 $a 0794
710 2 $a The University of North Carolina at Charlotte. $b Electrical Engineering. $3 3170016
773 0 $t Masters Abstracts International $g 82-11.
790 $a 0694
791 $a M.S.
792 $a 2021
793 $a English
856 4 0 $u https://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28496958