Drones

Whisper Drone could stop the whining

Whisper Drone could stop the w...
The prototype Whisper Drone in flight
The prototype Whisper Drone in flight
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Instead of the traditional propellers, the Whisper Drone utilizes ring-shaped vaned rotors
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Instead of the traditional propellers, the Whisper Drone utilizes ring-shaped vaned rotors
A close-up of one of the Whisper Drone's rotors
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A close-up of one of the Whisper Drone's rotors
The prototype Whisper Drone in flight
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The prototype Whisper Drone in flight
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Multicopter drones are neat and everything, but they do make a high-pitched whine – just image how annoying the sound of a large passenger-carrying version might be. It was with this in mind that electrical engineer Derek Schwartz recently went to Kickstarter with his Whisper Drone.

Currently in prototype form, the Whisper Drone mostly looks like a regular consumer quadcopter. Instead of the traditional propellers, however, it utilizes ring-shaped vaned rotors that Schwartz invented. These still provide static thrust – although currently with not as much efficiency as a regular propeller – yet produce a sort of whooshing sound as opposed to a whine.

Derek tells us it's also likely that his polyurethane foam rotors are more collision-resistant than more fragile traditional props, and that because their internal stresses are lower, they can be constructed from a smaller amount of material while offering the same amount of strength.

Instead of the traditional propellers, the Whisper Drone utilizes ring-shaped vaned rotors
Instead of the traditional propellers, the Whisper Drone utilizes ring-shaped vaned rotors

Additionally, they should be more resistant to vortex ring states. "The thick layer of accelerated air caused by the tall vanes seems to provide some insulation from downward flows of turbulent air," he tells us. "To my understanding, recirculated turbulent air sucked down into the conventional rotors can cause catastrophic loss of lift when VTOL [Vertical Take-Off and Landing] rotorcraft descend."

Schwartz adds that with each prototype he makes, the thrust efficiency improves. Even if it never quite matches the efficiency of a regular prop, however, his invention could conceivably still be applied to drones utilizing a hybrid system.

"The downward flow of air generated by operation of the rotor is located at the periphery, which opens up space on the interior," he explains. "An independently driven traditional propeller, or other means of thrust could be placed in that area as a source of alternative/supplemental thrust. As an example, a future craft might go into 'low noise mode' around populated areas by increasing power to the Whisper Drone's ring-like rotor, and decreasing power from the traditional propeller which could be placed in that central cylindrical area."

The current Kickstarter campaign is aimed at raising money to further develop the technology. A pledge of US$395 will get backers a Whisper Drone quadcopter with a remote-control unit, when and if the funding goal is met.

You can see and hear the prototype in flight, via the link below.

Source: Kickstarter

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7 comments
Roger Garrett
Go listen to the video on their Kickstarter page. It's still one hell of a noisy drone. So now it whooshes real loud instead of whining real loud.
nazza
How is a centrifugal fan a new invention?
DFrancis
How does the proposed design compare with similar blades but with only a simple fence or winglet at the blade tips instead of the unbroken annulus of the test vehicle?
IanL
I agree with Nazza; This is nothing more than a Centrifugal Pump based fan blade configuration and I don't see how it can be deemed innovative or patentable. Indeed, publishing it on Kickstarter etc implies the Patent attempt may well fail; especially if a Patent hasn't yet been filed as it has now been publicly disclosed. I've also put a comment on the Kickstarter page about this but also queried why the 'designer' has utilised an 'Open' fan design which by its very nature will be highly inefficient. Given the greater fan blade area this should produce much more lift force than a convention prop at the same rotating speed. But centrifugal forces will play big roll in this too as rotation speed increases. There is such an easy answer to greatly improve lift but clearly not considered :-) I've tested it with a design to utilise the "Coanda" effect with good results.
fb36
IMHO, if the goal is a silent propeller (for air/water), then the/a solution would be, a screw-propeller (a propeller shaped like a helicoid)! (And I think, more turns it has, more silent it would be!)
BrianK56
I guess if you fly, you're going to have noise.
Douglas Bennett Rogers
This is used to get compact size on air conditioning systems where weight is not a problem.