The source of the dc fan noise analysis
the first point. The vibration of the blade: generally made of plastic fan blade has a certain toughness, can withstand a certain degree of physical deformation, also in the process of pushing air because of mechanical vibration, but generally small. Another serious vibration is due to the blade quality distribution, center of mass and rotation axis eccentricity. When the door leaf area ( Quality) Or eccentricity larger cases, may drive the fan and radiator overall vibration occurs, and then spread to the whole case. In the event of such a phenomenon, should doubt fan quality and working condition.
the second point. Bearing friction and vibration: not only the noise, and impact performance, shorten the device life, reduce the efficiency of energy utilization, is as far as possible to solve the key technical problems in product design.
the third point. Wind: the flow of air between blunt talk to each other, with the surrounding objects, friction, and the separation of blade for air, periodic supply air pulse power, etc. , will produce noise. The faster the air velocity, turbulence, the more often wind noise is bigger, and will increase with the increase of wind speed in acceleration. Common in axial flow fan blades and the space between the casing outside the joints of the flyback airflow, produce a wind noise at the same time, more can cause adverse effect to air volume, is therefore a flange, side in the wind, and so on to improve design.