What are the factors that affect the noise of the 'car cooling fan'?

What are the factors that affect the noise of 'car cooling fans'? u003cbru003e u003cbru003e　　Fan noise is related to friction and air flow. The higher the fan speed and the greater the air volume, the greater the noise caused, and the vibration of the fan itself is also a factor that cannot be ignored. Of course, the vibration of a high-quality fan is very small, but the first two are difficult to overcome. To solve this problem, we can try to use a larger fan. When the air volume is the same, the working noise of the large fan at a lower speed should be smaller than that of the small fan at a high speed. Another factor that we easily overlook is the bearing of the fan. As the fan rotates at a high speed, there is friction and collision between the shaft and the bearing, so it is also a major source of fan noise. u003cbru003e u003cbru003e　　 In addition to the heat dissipation effect, the noise of the fan is also a common concern. Fan noise is the size of the noise generated by the fan when it is working, which is affected by many factors, and the unit is decibel (dB). When measuring the noise of the fan, it needs to be carried out in an anechoic room with a noise of less than 17dB, one meter away from the fan, and aligned with the fan's air inlet along the direction of the fan's shaft, and the A-weighted method is used for measurement. The spectral characteristics of fan noise are also very important. Therefore, it is necessary to record the frequency distribution of fan noise with a spectrum analyzer. Generally, the fan noise is required to be as small as possible, and there should be no abnormal noise. u003cbru003e u003cbru003e u003cbru003e u003cbru003eRecommendation: DC blower manufacturer http:///products-detail.asp?cpidu003d46