The formula for calculating airflow is fan airflow is equal to the product of the area ventilated by the fan and the plane velocity of that area.
Air volume is the total volume of air sent out or drawn in by an air-cooled radiator fan per minute, if calculated in cubic feet, the unit is CFM; if calculated in cubic meters, it is CMM, radiator products are often used in the unit of air volume is CFM.
Plane speed is certain, the larger the outer diameter of the fan blades, the larger the ventilated area, the greater the air volume. The larger the air volume, the greater the heat absorption of cold air, air flow transfer can take away more heat, the more obvious cooling effect.
Expanded information:
1, the ventilated area is the exit area minus the The projected area at the vortex tongue. Plane velocity is the speed of gas movement of the airflow through the entire plane in meters per second.
2, in the case of the same material of the heat sink, the air volume is the most important indicator of the air-cooled radiator cooling capacity. Obviously, the larger the air volume, the higher the cooling capacity of the radiator. This is because the heat capacity of the air is certain, a larger air volume, that is, more air per unit time can take away more heat. Of course, the cooling effect of the same air volume is related to the way the wind flows.
Reference:
Baidu Encyclopedia-Air Volume