When the blade generates vortex, noise will also be generated during the operation of the cooling fan, and vortex will be generated at the rear of the moving wing, which will not only reduce the efficiency of the fan, but also generate noise. During the operation of the fan, eddy currents will be generated at the rear of the moving wing, which will not only reduce the efficiency of the fan, but also generate noise. In order to reduce this phenomenon, the installation angle of the blade should not be too large, the curvature of the blade should be smooth, and it should not change too much suddenly. In order to reduce this phenomenon, the installation angle of the blade should not be too large, the curvature of the blade should be smooth, and it should not change too much suddenly.

2 noise caused by blade rotation

When the blade rotates, it can cause friction or impact with the air. When the blade rotates, it will cause friction or impact with the air. The faster the speed, the higher the frequency of the connected air and the louder the noise. This phenomenon becomes more pronounced as the width or thickness of the blade increases. This phenomenon becomes more pronounced as the width or thickness of the blade increases. The frequency of the noise is synthesized from multiple frequencies, all of which are related to the speed of the fan. The frequency of the noise is synthesized from multiple frequencies, all of which are related to the speed of the cooling fan.

3 fans

The noise is not only the fixed noise of the fan itself, but also many noise sources, such as abnormal noise caused by insufficient accuracy, improper assembly or poor bearing maintenance. In addition to the fixed noise of the fan itself, there are many noise sources, such as abnormal noise caused by insufficient accuracy, improper assembly, or poor bearing maintenance. Motors also generate noise. Some noise is caused by poor design or poor manufacturing quality control, but sometimes by internal and external cooling fans of the motor. Motors also generate noise. Some noise is caused by poor design or poor manufacturing quality control, but sometimes by internal and external cooling fans of the motor. Gears and belts also generate noise due to friction. Gears and belts also generate noise due to friction. Noise from other structural resonances cannot be ignored, which is sometimes caused by physical imbalance. Resonance of other structures

4 Noise caused by joint resonance between the pipe and the inner surface of the fan casing

It should be flat to avoid rough and tearing sounds. The connection between the inner surface of the pipe and the fan casing should be smooth to avoid rough and tearing sounds. However, due to the resonance of the connection pipe, the subtle sound becomes louder, resulting in greater noise. However, due to the resonance of the connection pipe, the subtle sound becomes louder, resulting in greater noise. In the design, the exterior of the duct can sometimes be covered with sound-proof materials to reduce noise. In the design, the exterior of the duct can sometimes be covered with sound-proof materials to reduce noise.