Air Multiplier Technology — Bladeless Fan

I was really amazed to see this technology, how the air is produced with out any blades!
Know how this technology works in detail below:

The latest Air Multiplier Technology is highly complex and draws on aeronautics and jet-engine technologies. It generally works by suction of air into its base with an impeller which is an improvement on the larger models built on today’s modern jet fighters. So here is how the Dyson air multiplier works:

Step 1:

An energy efficient brushless 40 watt electric motor draws in up to a maximum of 27 litres per second through the little vents in the base of the air multiplier. The power consumption here is comparatively lower than the average power in conventional fans. This process is based on a blend of technologies made use of in jet engines and turbochargers producing a powerful flow of uninterrupted air.

Step 2:

The air is then gradually forced upward into the ring at pretty high speeds. It then makes an exit within the ring via very narrow 1/16th of an inch wide slits. The air then moves over the ring’s inner edge which is, in actual the most revolutionary part of the fan. This essentially has been designed in the same way as that of the wing profile and functions pretty much in the same manner as the wing.

Step 3:

The air behind the air multiplier is then drawn right into the flow of air by a process known as inducement. The air comes out of a 3mm slit built in the frame at a speed of 55mph.

Step 4:

The air then moves over a ramp which is shaped like an airfoil, which directs it outwards. This is the most important point as the surrounding air is gradually drawn into the flow of air that multiplies the original volume of air by about 15 times. As the fan does not have blades chopping the air, all the air which is propelled out is even compared to the conventional bladed fan which gives you irregular blasts to the face.

Overall the resulting air flow is really smooth and consistent without undesirable buffeting.

Story behind the Air Multipliers

Issues with traditional fans:

There has not been any marked improvement in the design and construction of electric fans since their invention in 1882, save for a few notable changes here and there including addition of grills, change of materials and integration of buttons for convenience. This said, traditional fans have not been able to do away with the fundamental problem of the blade chopping the air. And choppy air does cause annoyance and undesirable buffeting. Getting rid of the blades can put an end to buffeting and how on earth would you make a fan work without blades?

Behaviour of air at high speeds:

While engineers were developing the concept behind their Airblade hand dryer, they noted how air that is being accelerated at very high speeds through a narrow aperture led the surrounding air to be sucked in. And this phenomenon was later realized to be pretty useful, especially in a fan. Several number of tests followed to discover the ideal aperture width, dimensions of loop amplifier and ramp angle to come out with a fan with no blades.

Motor technology:

For generating a jet of air and making it powerful enough to function properly, the motor should be designed in a way so as to suck in more than 20 litres of air/second. The Dyson engineers were able to do this by designing a new sort of 3-dimensional impeller built with 9 fins that are asymmetrically aligned, blending technologies that are being employed in turbochargers and jet engines.

Testing airflow:

Next comes the testing of airflow smoothness, Engineers at Dyson made use of a technique known as the ‘Laser Doppler Anemometry’. Tiny particles in the count of millions were suitably injected into the flow of air for making flow patterns noticeable to laser technology. Totally 4 layers were made use of for tracking the direction and speed of the particles, consuming up to 2000 measurements/second. For creating a much detailed, comprehensive map of the air multiplier’s airflow, fluid dynamic engineers at Dyson had to carry about 4000000 velocity measurements. Though an engineer at Dyson had a bit of original idea in his mind, it took every little discipline from the manufacturer’s 350-solid and brilliant team of scientists and engineers to build the Air multiplier technology.