A cooling fan air volume and air pressure
air volume and air pressure there are two kinds of test methods, one is to use wind tunnel test instrument, the other is with double box method. But for the average user, there is no such equipment. Only according to the data provided by the manufacturer as reference, ultimately depends on cooling effect. Macro morning electronic technology co. , LTD. Have professional equipment to test a cooling fan air volume and air pressure, guarantee to provide customers with high quality cooling fans.
air volume is refers to the product rate of fan ventilation area is flat. Ventilation area is the projection area of the outlet of area minus vortex tongue. Plane speed is gas velocity of the airflow through the whole plane, unit is the m3 / s. Plane speed is constant, the fan under the wheel diameter, the greater the ventilation area, the greater the air volume is larger. The plane speed is determined by the rotor speed and wind pressure. When a certain ventilation area, the greater the plane speed, air volume is larger. The bigger air volume and air heat absorption capacity, and the air flow when the transfer can take weeks to take more heat, fan heat effect is more obvious. Wenling city chi automotive air conditioning manufacturing co. , LTD. A professional equipment testing air volume and air pressure.
for normal ventilation, need to overcome the resistance inside the fan ventilation trip, fan must have overcome the pressure of the air resistance, the change of the measured pressure value, called static pressure, the maximum static pressure and atmospheric pressure differential pressure. It is the gas pressure, the role of parallel to the surface static pressure is through hole measured perpendicular to the surface. What we need in the gas flow kinetic energy into pressure form called dynamic pressure.
to achieve the purpose of the air supply, it is necessary to have static pressure and dynamic pressure. Total pressure to the algebraic sum of static pressure and dynamic pressure, total pressure refers to the total pressure given by the fan in the increase, the fan of total pressure difference between exports and imports. In practical applications, the nominal maximum wind quantity is not the actual fan heat get delivery, air volume is big, does not represent the ventilation ability. Due to air flow, air flow in the flow path will meet fan heat collection or element block, the impedance will limit the free flow of air. Increase the air volume, air pressure will decrease. So there must be a best operating point, namely the fan performance curve and wind resistance curve intersection. In working point, the fan characteristic curve slope of the youngest, and the system characteristic curve of the lowest rate. Note that the fan static efficiency ( Airflow by air pressure present electricity) For the best. Sometimes, of course, in order to reduce system impedance, even use smaller fan, can also get the same air volume.