Leonardo da Vinci’s “helicopter” design could make drones quieter

A flying machine designed by Leonardo da Vinci may have been functional and much quieter than modern drone conceptions.

Rajat Mittal at Johns Hopkins University in Maryland and his colleagues found that Da Vinci’s “air screw”, which he proposed while working as a military engineer in 1480 but never built or tested, may require less power to generate the same quantity of lifting as a conventional drone rotor.

The machine is similar to the screw of an archimede, a propeller -shaped pump that carries the water when it runs. Da Vinci was considering the air screw as being fueled by humans, which would have made it difficult to take off due to the weight. But with light electric motors that turn the rotor, it could have flyed.

Mittal and his team built a simulation of the screw and placed it in a virtual blower to see how it would occur while hovering in place, testing it at different rotation speeds and comparing it with a conventional drone rotor with two blades.

They found that the air screw could generate the same amount of lift while turning more slowly, which means that it would consume less power.

By measuring the pressure and wind flow models that moved around the virtual screw, Mittal and its team could also calculate the quantity of its it could produce, which they found less than conventional design for the same amount of lifting.

“We were surprised,” said Mittal. “We went by thinking that because the shape of this spiral screw is simply completely ad hoc, it was intuitive that aerodynamic performance was so bad that we could not obtain improvements compared to conventional blades.”

Mittal and his team now want to see if they can improve the design of Da Vinci to make it more effective while keeping its noise reduction qualities, he said.

As drones are increasingly used in cities, for example for home deliveries or emergency services, noise pollution has become more a problem, leading to researchers looking for new rotor conceptions that create less noise for a similar amount of lift.

“The authors do a good job to say that if you can create the same push by becoming more slowly, which Da Vinci [rotor] The fact, then the noise will be less, “explains Sheryl thanks to the University of Boston in the Massachusetts.” It is not necessary that it is the design of Vinci to achieve it, but it is good that Da Vinci has. »»

However, to show that the design of Da Vinci could be useful in the scenarios of the real world, they should test how it behaves while flying in the air, rather than hovering, as well as considering how the additional weight of the rotor could affect the performances, says Grace.

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