A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars
When air flows through the mirrors, A-pillars, and other surfaces of a passenger car, airflow separation occurs to generate vorticity and generates aerodynamic noise. The dipole noise source is the main source of aerodynamic noise when the passenger car is travelling at high speed. In order to revea...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-09-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/13/19/10651 |
| _version_ | 1797576226780479488 |
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| author | Siwen Zhang Jian Pang Yiping Wang Rui Ma Hao Jiang Wenyu Jia Xiaomin Xu Jinhao Xia |
| author_facet | Siwen Zhang Jian Pang Yiping Wang Rui Ma Hao Jiang Wenyu Jia Xiaomin Xu Jinhao Xia |
| author_sort | Siwen Zhang |
| collection | DOAJ |
| description | When air flows through the mirrors, A-pillars, and other surfaces of a passenger car, airflow separation occurs to generate vorticity and generates aerodynamic noise. The dipole noise source is the main source of aerodynamic noise when the passenger car is travelling at high speed. In order to reveal the relationship between the physical quantities in the flow field and the intensity of the dipole noise source, this paper equates each dipole noise source to a sphere radiating noise to the outside. The acoustic wave fluctuation equations expressed as spherical coordinates are combined with the acoustic boundary conditions and the equations of motion of an ideal fluid medium to obtain the relationship between the intensity of the dipole noise source and the flow velocity and vorticity in the flow field. Then, through flow field simulation, we establish a method of identifying the dipole noise source and its distribution area, and analyze the generation mechanism of the dipole noise source. Through the analysis, it is concluded that the dipole noise sources are mainly concentrated in the airflow separation areas, which easily generate vortices. The size of the vorticity is the key factor affecting the intensity of the dipole noise source. When the intensity of the dipole noise source reaches its peak, the direction of the flow vorticity is perpendicular to the direction of the flow velocity and the peak of the flow velocity occurs before the peak of the dipole noise source, which indicates that the angle between the flow vorticity and the flow velocity, as well as the flow velocity, also has a certain effect on the generation of the dipole noise source. |
| first_indexed | 2024-03-10T21:49:18Z |
| format | Article |
| id | doaj.art-2299b0e3788441639789ceb51737174a |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T21:49:18Z |
| publishDate | 2023-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Applied Sciences |
| spelling | doaj.art-2299b0e3788441639789ceb51737174a2023-11-19T14:02:19ZengMDPI AGApplied Sciences2076-34172023-09-0113191065110.3390/app131910651A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger CarsSiwen Zhang0Jian Pang1Yiping Wang2Rui Ma3Hao Jiang4Wenyu Jia5Xiaomin Xu6Jinhao Xia7State Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401120, ChinaState Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401120, ChinaHubei Key Laboratory of Modern Auto Parts Technology, Wuhan University of Technology, Wuhan 430070, ChinaHubei Key Laboratory of Modern Auto Parts Technology, Wuhan University of Technology, Wuhan 430070, ChinaState Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401120, ChinaState Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401120, ChinaState Key Laboratory of Vehicle NVH and Safety Technology, Chongqing 401120, ChinaHubei Key Laboratory of Modern Auto Parts Technology, Wuhan University of Technology, Wuhan 430070, ChinaWhen air flows through the mirrors, A-pillars, and other surfaces of a passenger car, airflow separation occurs to generate vorticity and generates aerodynamic noise. The dipole noise source is the main source of aerodynamic noise when the passenger car is travelling at high speed. In order to reveal the relationship between the physical quantities in the flow field and the intensity of the dipole noise source, this paper equates each dipole noise source to a sphere radiating noise to the outside. The acoustic wave fluctuation equations expressed as spherical coordinates are combined with the acoustic boundary conditions and the equations of motion of an ideal fluid medium to obtain the relationship between the intensity of the dipole noise source and the flow velocity and vorticity in the flow field. Then, through flow field simulation, we establish a method of identifying the dipole noise source and its distribution area, and analyze the generation mechanism of the dipole noise source. Through the analysis, it is concluded that the dipole noise sources are mainly concentrated in the airflow separation areas, which easily generate vortices. The size of the vorticity is the key factor affecting the intensity of the dipole noise source. When the intensity of the dipole noise source reaches its peak, the direction of the flow vorticity is perpendicular to the direction of the flow velocity and the peak of the flow velocity occurs before the peak of the dipole noise source, which indicates that the angle between the flow vorticity and the flow velocity, as well as the flow velocity, also has a certain effect on the generation of the dipole noise source.https://www.mdpi.com/2076-3417/13/19/10651passenger vehiclethe intensity of dipole noise sourcesgeneration mechanismflow field simulationvorticityair flow velocity |
| spellingShingle | Siwen Zhang Jian Pang Yiping Wang Rui Ma Hao Jiang Wenyu Jia Xiaomin Xu Jinhao Xia A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars Applied Sciences passenger vehicle the intensity of dipole noise sources generation mechanism flow field simulation vorticity air flow velocity |
| title | A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars |
| title_full | A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars |
| title_fullStr | A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars |
| title_full_unstemmed | A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars |
| title_short | A Study of the Relationship between Dipole Noise Sources and the Flow Field Parameters around the Rearview Mirror of Passenger Cars |
| title_sort | study of the relationship between dipole noise sources and the flow field parameters around the rearview mirror of passenger cars |
| topic | passenger vehicle the intensity of dipole noise sources generation mechanism flow field simulation vorticity air flow velocity |
| url | https://www.mdpi.com/2076-3417/13/19/10651 |
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