What is the principle that a fan without blades will blow out?

The base of the bladeless fan is equipped with a centrifugal compressor, and the air around the base is sucked, pressurized and pushed to the hollow tubular ring at the top of the fan by rotating blades. One end of the tubular ring is provided with a slit, air is ejected from the slit, and the ejection direction makes the ejected air advance along the inner wall of the tubular ring; Because the cross section of the inner wall is wing-shaped, based on Bernoulli's law, a low pressure is formed on the inner wall of one side of the gas injection ring, so that the central front part of the ring is lower than the rear part, the air in the rear part is pulled forward, and a large amount of air in the ring is sucked out and ejected. In james dyson's original design, a brushless motor was used in the base to push the compressor to suck in 27L of air per second, while the annular air outlet device ejected 405L of air per second. Sir james dyson, an industrial designer, named his fan "Air Multi-effect Device". Performance The Spanish consumer protection organization Organizació ndeConsumer Syusualios tested Dyson's first air multiplier (AM0 1) and evaluated the longer and more stable airflow. It is found that its maximum setting needs 40W, moving at 2700 m/h ... but it is noisier and more expensive than the vane fan (300-400 Euros to 20 Euros). Another test found that the power consumption of AM0 1 varied between 2-3W and 31W. The air volume, noise level and power of Geek.comAM06 are measured, and it is found that the wind speed is similar to the dynamic air volume per second except for the first setting, and it is quieter (2- 10dB) and more energy-saving. According to the setting, the efficiency of moving air volume per unit is achieved (6-3 times). It is reported that the highest setting produced 1 150 ft/min (1950 m/h) and 548 ft/min (2.7 m/s). The volume of an ordinary fan equivalent to $80 is about twice that of a 15 fan, and the wind speed is roughly equivalent to both. Under this setting, the noise generated by AM06 is lower than that of ordinary fans by 10dB, which is 20W, and ordinary models are 60W and 40W.