Axial fan, fan is a fan, fan whose blades push air to flow in the same direction as the shaft when working.
This classification of the direction of the air pushed by the blades and the direction of the shaft can beCooling fanDivided into: axial fan, centrifugal fan (the inlet is along the axis direction, but the outlet is perpendicular to the axis direction), cross-flow (cross-flow) fan (the inlet and outlet of this fan are perpendicular to the axis), mixed flow Fan (the inlet of the mixed flow fan is along the axis, but the outlet is along the diagonal direction of the axis and the vertical axis).
Axial fan | air supply form of fan. A wide range of forms is the use of axial fans, which blow downward. The reason why it is so popular is that the comprehensive effect is wrapped well and the cost is low. In addition, it seems to be becoming more and more common to reverse the direction of the axial fan into the form of upward ventilation.
The difference between the two forms of air supply lies in the different forms of air flow. When blowing, turbulent flow is generated, and the wind pressure is large but vulnerable to resistance loss. When pumping, laminar flow is generated, and the wind pressure is small but the air flow is stable. In theory, the heat transfer efficiency of turbulent flow is much greater than that of laminar flow, so it has become the mainstream design form. However, in some heat sink designs (such as too tight fins), the airflow is greatly hindered by the heat sink, and the use of exhaust air may have a better effect.
How to judge which air supply method to use? When the heat in the equipment is relatively scattered and evenly distributed, and the wind resistance of the cooling surface is relatively small, exhaust cooling is usually used; when the heat distribution in the equipment is uneven, the wind resistance is large, and the components In many cases, blast cooling is usually used. When necessary, the fans can be connected in series (increasing wind pressure), parallel (increasing air volume) or mixed.
Cross-flow fan is also called cross-flow fan, so it refers to the same thing, but the name is different!
The cross-flow fan, also known as the cross-flow fan, was proposed by French engineer Mortier in 1892. The impeller is multi-leaf, long round cylinder, front multi-wing blade. When the impeller rotates, the airflow enters the blade cascade from the opening of the impeller, passes through the inside of the impeller, and is discharged into the volute from the other side of the blade cascade to form the working airflow. The flow inside the impeller is complex and the velocity field is unstable. There is a vortex in the impeller, the middle is located near the volute tongue. The presence of the vortex causes a circulating flow at the output of the impeller. Outside the vortex, the streamlines inside the impeller are arc-shaped. Therefore, the speed at each point on the outer periphery of the impeller is not uniform. The closer to the middle of the vortex, the greater the velocity, and the closer to the shell, the smaller the velocity.
The speed and pressure of the air flow at the outlet of the fan are not uniform, so the flow coefficient and pressure coefficient of the fan are average. The vortex position has a great influence on the performance of the cross flow fan. The middle of the vortex is close to the inner circumference of the impeller, close to the volute tongue, the fan performance is better; the middle of the vortex is far away from the vortex tongue, the circulation flow area increases, the fan efficiency drops to the bottom, and the flow instability increases.
These are other categories of fans. For more information, please consult our official website!