How do you let the radiator cooling fan noise reducing

Proper use of radiator cooling fan will drop at the end of its noise, together to get to know below: 1. System impedance: between a casing into the tuyere and outlet range 60% to 80% of all system impedance, the greater the additional air, noise is relatively high. The higher the system impedance, needed for the cooling air flow is larger, so in order to reduced the noise is small, the system impedance must be reduced to very low levels. 2. Airflow disturbing: along the flow path encountered obstacles caused by the interference flow noise. So all obstacles, especially in the key into the scope of tuyere and the outlet, must avoid, for decreasing noise. 3. Cooling fan speed and size: due to the high speed cooling produce larger than the low speed cooling fan noise, so should as far as possible to try and choose low speed cooling fan. And a big size and low speed of cooling fan, often than small size, high speed of cooling fan, quiet when conveying the same volume. 4. Temperature: a cooling system, and the permissible temperature rise is inversely proportional to the required air volume. Allow temperature increased slightly, can substantially reduce the air volume required. Therefore, if the limitation on the strong and allow temperature rise slightly relax, the required air volume will drop at the end of the bottom of the noise can be reduced. 5. Vibration: in some situations, the weight of the whole system is very light, or the system must operate in accordance with some regulations, especially recommended the soft isolation equipment, in order to avoid the cooling fan vibration transfer. 6. Voltage: variable voltage changes will affect the noise level. Added to the cooling fan of the higher the voltage, because the higher speed, vibration is big, the greater the noise also. 7. Design considerations: every component design, constitute the cooling fan will affect the noise level.