Dyson calls it an "air multiplier", but everywhere you see this, it's called a bladeless fan. A fan with no blades? Where does the air come from? Apparently, it's drawn into the bottom of the gadget, where there is a, yes, a conventional fan with blades (just well hidden). The air is fed up to the big loopy round part (for want of a more descriptive name). Somehow, this process also draws in more air from behind the fan and around the edges of the fan. Which gives you lots of air blowing.
Dyson (the... READ ON