Electric fans haven’t changed much since they were invented in 1882—blades slicing through the air to push it forward. When the engineers at Dyson first began working on a fan without blades, they started with pressurized air, forcing it through narrow apertures to create jets.But a breakthrough came when they noticed that accelerating air over a ramp amplified it 10-20 times.
Fluid dynamics engineers spent four years ‘‘running hundreds of simulations to precisely measure and optimize the machine’s aperture and airfoil-shaped ramp”, and air fluctuations were mapped using laser doppler annometry, finally revealing the ideal ramp angle, aperture width and loop amplifier dimensions.
‘‘We realized that this inducement, or multiplication, effect could be further enhanced by passing airflow over a ramp,” says inventor James Dyson. ‘‘And, of course, this was the point where the idea of a bladeless fan became a real possibility.”
Also See |Bladless Wonder (PDF)
Photographs: Priyanka Parashar/Mint