AC 9225 92*92*25mm Big Air Flow Low Noise AC Axial Fan

Die-cast aluminum housing

Glass fiber reinforced plastic: Impeller and housing PBT are UL 94V0 rating

Impedance protected

Leader wire or terminal is available

Operating temperature:

Ball bearing: -30℃to +75℃

Sleeve bearing: -10℃to +70

The total noise level of the fan is proportional to the sixth power of blade speed. Based on analysis, the fan noise source is primarily dipole in nature and caused by blade interaction with upper air pulses flowing through the fan. Two discrete frequency noise sources can be identified: propeller-type noise generated by rotor blade pressure fields and blade pulse dynamic noise resulting from aerodynamic interference. The distance between aerodynamic and static blades plays a critical role in interference noise, as potential flow changes and wake velocity alterations impact acoustic radiation generated by lift pulsation on neighboring blades. This effect depends on the ratio of sound wave wavelength associated with lift pulsation to size of blades acting as barriers; significant changes in radiation intensity occur when this ratio exceeds 2. Blade radiating area, distance between blade rows, and shape of velocity field waveform (i.e., blade load) are three key parameters affecting magnitude of interference noise. Very small spacing can have two acoustic effects.