The first time you see one of these bladeless fans it is a little surprising. It appears to blow air without any moving parts:
How does it work? Here's a nice explanation with images and video:
The Dyson fan has a conventional motor and fan blade in the base. The air flows from the base into the upper ring structure. No magic there. The magic is in the ring structure, where the air flows out a slit around the front edge of the ring. Here a process called inducement is put to work. The air flowing out of the slit recruits surrounding air because of the configuration of the slit. So now there is more air flowing through the ring structure than there would be from the base fan alone. Dyson claims that inducement creates a 15x amplification in airflow. Hence the name "Dyson Air Multiplier".
How does this inducement process work? You can see a dramatic example of it in the following video, where a single breath of air fills a large plastic bag by putting the principle to work:
More info on the video: Windbag - The Bernoulli Bag
Something similar lies at the heart of a Bunsen burner. The flow of gas through a Venturi area brings in a large volume of surrounding air to mix with the gas and provide a hotter flame, as demonstrated here:
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