How to choose the right fan blade design for your portable fan?

The design of the portable fan's leaf surface and the number of leaves are important factors that affect the feeling of blowing wind.

A reasonable leaf design can ensure that the wind blown out is both soft and even, and the range reached is also larger, closer to the effect of natural wind, so that you can enjoy the spring breeze.
First. What is the working principle of the portable fan?

How natural air works
The principle of natural wind is that as the heated air expands and becomes lighter, the cold air is added to the gap; the hot air will gradually cool down and finally become cold air and then fall back to the ground, and this air flow produces wind.

role of the fan

Similarly, the role of the fan is to convert the electric potential into wind energy, the size of the wind speed is determined by the speed of the motor, the use of motor rotation driven by the rotation of the fan blade, the upper air force "flow away", the negative pressure (i.e., below atmospheric pressure), the lower air "into", forming a continuous air flow. A continuous flow of air is formed. Therefore, the fan blade is to determine the direction of the wind source, a reasonable fan blade design can improve the efficiency of potential energy conversion, both to ensure the quality of the wind and save electricity.

Second, most of the existing portable  fans are three-blade and five-blade, what is the difference between three-blade and five-blade electric fans?

1,The single blade area of a three-blade fan is larger than that of a five-blade, and the range of air action is increased, which will produce more noise; however, the mold and production of a three-blade fan is much easier and cheaper than that of a five-blade fan, and the fan blade root is wider at the connection with the central shaft, so the blades of a three-blade fan using the same materials are much stronger than those of a five-blade fan. Therefore, in general, most low-noise fans are five-bladed; and five-bladed fans have relatively softer wind.

2, Five-blade is certainly better than three-blade, after the fan from three-blade into five-blade, the blade becomes narrower, to achieve the same strength, it requires a thicker steel plate. In addition, the design of the blade shape, more complex than the original, with 50 tons of pressure stamping without molding, must open to 200 tons of pressure to do, the difficulty has increased quite a lot, the price is naturally high, the blade more wind is relatively softer point. The fan is a three-blade high speed, five-blade low speed, wind pressure is different, and the structure of the heat exchanger. Generally speaking, the five-blade expensive some.

3, the number of blades of the axial fan is generally an odd number, which is due to the time of dynamic balance correction, odd number of blades is easier to correct the center of rotation. If an even number of fan blades, easy to make the system resonance, if the blade material can not resist the fatigue generated by vibration, the blade or bearing is very easy to fracture, so the axis is not symmetrical odd number of fan blades more appropriate. Propeller also applies the same principle.

Third, the fan's blade is not the more the better?

The answer is definitely no.
Generally speaking, the more fan blades a fan has, the better the air delivery effect. Because the fan blade can cut the "wind" into smaller pieces, making the wind softer and quieter. However, more blades means more load on the fan's motor, and too high a load will shorten the life of the fan's motor; in addition, too many fan blades will lead to less vibration in the surrounding air and less wind; the last and main reason is that in the new generation of fan motors we have developed, the fan starts to operate initially with the motor connected to the power supply, and the initial operation of the fan blades is caused by the The initial 3-blade fan first formed a reasonable mechanical power, 2 blades in a state of potential energy, easily drive a temporary potential energy does not have the blade, can save a lot of power to start, greatly improve the utilization rate, too much of the leaf surface will affect the fan's starting performance.
From the above analysis, it can be seen that the fan is not the more the better, the most appropriate is the 5 blade design is more reasonable.
Fourth, what is the shape of the fan blade?
Modern fans are generally bionic bird wing fan blade shape, just like the wings of a bird, the air behind the machine into the fan blade, and then sent forward, blade flow, low noise, in line with the principles of fluid dynamics. And HandFan now mainstream fan blade will also be based on the study of the wing after iteration, we based on the consideration of the fan page and motor starting performance, we combine bionics and physics together, set up a different page from the conventional, we designed three large blade in the middle sandwiched between three small blade, both to improve the fan starting performance, but also make the interval between the blade is large enough This is the reason why HandFan fans are more durable and comfortable than other brands of fans.

This article summarizes: the working principle of the fan is to use the electric potential energy to drive the fan blades to run so that the air pressure difference is formed, and the design of the fan blades determines the direction and quality of the wind, and the existing design of the number of fan blades is more recommended to use the fan with 5 blades; combined with the shape of the fan blades, we recommend choosing the more practical fan design with 3 large + 3 small blades.