Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan
Low-speed axial cooling fans are frequently used to manage engine temperature by ensuring that adequate quantities of air pass through heat exchangers, even at low vehicle speeds or in the idle condition. This study aims to provide a better understanding of the unsteady flow behavior around an autom...
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MDPI AG
2020-08-01
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| Series: | Applied Sciences |
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| Online Access: | https://www.mdpi.com/2076-3417/10/16/5432 |
| _version_ | 1797560023283400704 |
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| author | Jang-oh Mo Jae-hyuk Choi |
| author_facet | Jang-oh Mo Jae-hyuk Choi |
| author_sort | Jang-oh Mo |
| collection | DOAJ |
| description | Low-speed axial cooling fans are frequently used to manage engine temperature by ensuring that adequate quantities of air pass through heat exchangers, even at low vehicle speeds or in the idle condition. This study aims to provide a better understanding of the unsteady flow behavior around an automotive axial cooling fan with seven blades and its impact on the aerodynamic noise generation. Large Eddy Simulation (LES) near the near-field region and the Ffowcs-Williams and Hawkinbygs (FW-H) method were performed to analyze the flow characteristics around the fan and predict the aerodynamic noise emitted from the fan under a constant rotational speed of 2100 rpm. The simulation results for the velocity distributions and aerodynamic noise were compared with the experimental data measured by single hot-wire probe and in a dead-sound room. The results showed a comparatively good agreement upstream and downstream from the fan and at two different receivers of 0.5 m and 1.0 m. When the fan was rotating, a strong tonal noise numerically existed near the leading edge of the blades at the tip and amounted to 110 dB sound pressure level (SPL) caused by the increasing angles of attack with the increasing radial velocity near the ring, which caused the entire air foil to emit a low-frequency noise. Furthermore, the different SPL decay characteristics of approximately 5 dB in the near-field region and 6 dB in the far-field region were observed each time the distance from the fan doubles. The findings of this research can provide important insights into the design of axial fans with low noise and high performance. |
| first_indexed | 2024-03-10T17:53:33Z |
| format | Article |
| id | doaj.art-2175435602c1419abbed61b2a49ea4b6 |
| institution | Directory Open Access Journal |
| issn | 2076-3417 |
| language | English |
| last_indexed | 2024-03-10T17:53:33Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
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| spelling | doaj.art-2175435602c1419abbed61b2a49ea4b62023-11-20T09:15:32ZengMDPI AGApplied Sciences2076-34172020-08-011016543210.3390/app10165432Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling FanJang-oh Mo0Jae-hyuk Choi1Asia Affairs Center and Missouri International Training Institute, University of Missouri, Columbia, MO 65211, USADivision of Marine System Engineering, Korea Maritime and Ocean University, Busan 49112, KoreaLow-speed axial cooling fans are frequently used to manage engine temperature by ensuring that adequate quantities of air pass through heat exchangers, even at low vehicle speeds or in the idle condition. This study aims to provide a better understanding of the unsteady flow behavior around an automotive axial cooling fan with seven blades and its impact on the aerodynamic noise generation. Large Eddy Simulation (LES) near the near-field region and the Ffowcs-Williams and Hawkinbygs (FW-H) method were performed to analyze the flow characteristics around the fan and predict the aerodynamic noise emitted from the fan under a constant rotational speed of 2100 rpm. The simulation results for the velocity distributions and aerodynamic noise were compared with the experimental data measured by single hot-wire probe and in a dead-sound room. The results showed a comparatively good agreement upstream and downstream from the fan and at two different receivers of 0.5 m and 1.0 m. When the fan was rotating, a strong tonal noise numerically existed near the leading edge of the blades at the tip and amounted to 110 dB sound pressure level (SPL) caused by the increasing angles of attack with the increasing radial velocity near the ring, which caused the entire air foil to emit a low-frequency noise. Furthermore, the different SPL decay characteristics of approximately 5 dB in the near-field region and 6 dB in the far-field region were observed each time the distance from the fan doubles. The findings of this research can provide important insights into the design of axial fans with low noise and high performance.https://www.mdpi.com/2076-3417/10/16/5432axial cooling fanlarge eddy simulation (LES)Ffowcs-Williams and Hawkinbygs (FW-H) modeltonal noisedipole sourceOSPL |
| spellingShingle | Jang-oh Mo Jae-hyuk Choi Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan Applied Sciences axial cooling fan large eddy simulation (LES) Ffowcs-Williams and Hawkinbygs (FW-H) model tonal noise dipole source OSPL |
| title | Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan |
| title_full | Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan |
| title_fullStr | Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan |
| title_full_unstemmed | Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan |
| title_short | Numerical Investigation of Unsteady Flow and Aerodynamic Noise Characteristics of an Automotive Axial Cooling Fan |
| title_sort | numerical investigation of unsteady flow and aerodynamic noise characteristics of an automotive axial cooling fan |
| topic | axial cooling fan large eddy simulation (LES) Ffowcs-Williams and Hawkinbygs (FW-H) model tonal noise dipole source OSPL |
| url | https://www.mdpi.com/2076-3417/10/16/5432 |
| work_keys_str_mv | AT jangohmo numericalinvestigationofunsteadyflowandaerodynamicnoisecharacteristicsofanautomotiveaxialcoolingfan AT jaehyukchoi numericalinvestigationofunsteadyflowandaerodynamicnoisecharacteristicsofanautomotiveaxialcoolingfan |