When the heat reaches the top of the radiator, it needs to be dissipated to the surrounding environment as soon as possible. For air-cooled radiators, it is necessary to exchange heat with the surrounding air. At this time, heat is transferred between two different media. The formula to follow is Q=α XAX ΔT, where ΔT is the temperature difference between the two media, that is, the temperature difference between the radiator and the surrounding air; and α is the fluid The thermal conductivity is a fixed value after the material of the heat sink and the air composition are determined; the most important A is the contact area between the heat sink and the air. Under the premise that other conditions remain unchanged, such as the volume of the heat sink, it will generally have Due to the limitation, the space in the case is limited, which will increase the difficulty of installation if it is too large. By changing the shape of the radiator, increasing its contact area with the air and increasing the heat exchange area are effective means to improve heat dissipation efficiency. To achieve this, the surface area is generally increased by using a fin design supplemented by surface roughening or threads.
When the heat is transferred to the air, the temperature of the air in contact with the heat sink will rise rapidly. At this time, the hot air should try to take away the heat with the surrounding cold air through heat exchange methods such as convection. For air-cooled radiators The main method is to increase the speed of air flow and use a fan to achieve forced convection. This is mainly related to the design of the fan and the wind speed. The efficiency of the radiator fan (such as flow rate, wind pressure) mainly depends on the fan blade diameter, axial length, fan speed and fan blade shape. The flow rate of the fan mostly adopts CFM as the unit (English system, cubic feet/minute), a CFM is about 0.028mm3/minute flow.