Leonardo da Vinci design solves modern drone noise problems

Drones deliver packages, inspect bridges, and shoot video, but their high‑pitched whine still irritates neighbors and wildlife. Engineers want rotor shapes that hush the noise without draining batteries.

One possible design comes from a 15th‑century notebook by Leonardo da Vinci, a continuous spiral rotor he called an “aerial screw.” New simulations suggest that it can lift a modern drone while saving power.

Rajat Mittal of Johns Hopkins University led a study that puts the Renaissance sketch to the test.

Da Vinci’s drone idea

Leonardo da Vinci pursued flight long before airplanes – sketching wings, parachutes, and the spiral screw that inspired the helicopter dream. His notebooks show careful airflow doodles even though the science of lift would not be formalized for centuries.

The spiral looks like an overgrown Archimedes’ screw, a water‑lifting helix from ancient Greece, except it twists upward to push air downward. Historians note that da Vinci often borrowed proven mechanical ideas for new purposes.

Human muscle could never spin the heavy canvas screw fast enough, so the contraption stayed on paper. Lightweight electric motors and carbon‑fiber skins finally give the old idea a chance to rise.

A small prototype built at the University of Maryland in 2020 confirmed the screw can generate lift, though efficiency data were thin. The new work attacks that gap with supercomputer fidelity.

Testing the spiral rotor

Mittal’s team rebuilt the rotor in code and ran direct numerical simulations. The model tracked every swirl of air around the spiral as it hovered.

The exercise probed aerodynamics and aeroacoustics at several Reynolds number values – a parameter that links size, speed, and viscosity. Matching those numbers to typical small drones let the results translate to real rotors.

“We were surprised,” said Mittal. The screw needed roughly 20 percent less mechanical power than a two‑blade prop to hold the same weight.

Because the spiral presents more surface but turns slower, the simulation predicted a weaker pressure pulse and therefore a quieter signature. Earlier modeling of large‑area insect‑inspired rotors hinted at the same trend.

Spiral rotors can reduce drone noise

Community annoyance rises sharply when drone flights repeat every few minutes, a NASA laboratory study found last year. People rated even modest noise harsher when it came in clusters.

Complaints back that up; the Federal Aviation Administration logged 8,746 aircraft noise reports in the first quarter of 2025, with just 60 residents submitting 72 percent of them. Drones are included in the totals for many cities.

“It doesn’t have to be the da Vinci design to achieve this, but it is nice that da Vinci’s does,” said Sheryl Grace of Boston University.

A rotor that spins 1,500 revolutions per minute slower cuts broadband noise roughly in half, according to the new simulation. That drop matters more than raw loudness because the whine often falls in the most sensitive range of human hearing.

Da Vinci’s design for drone deliveries

Drone couriers face strict noise limits near hospitals, schools, and wildlife preserves. A built‑in silencer would lighten regulatory burdens without adding extra shrouds or foam.

The spiral also trims energy burn, extending range or freeing capacity for heavier batteries. Efficiency gains remain welcome while lithium prices climb.

Challenges persist: forward flight introduces side loads the screw has not yet faced, and the spiral adds mass compared with thin blades. Structural tests will need to prove the membrane can survive sudden gusts.

Even so, quieter fleets could reduce the buffer zones that push drone depots to industrial parks and away from customers, shrinking the road miles trucks must still cover.

Future plans for spiral rotors

Mittal’s group plans to tweak pitch, taper, and turn count to squeeze more lift per square inch while keeping the low hum. The same code that vetted the classic shape can rank new variants in days instead of months.

Lab prototypes will follow, spun by off‑the‑shelf hobby motors to compare thrust and decibels against standard props. Microphones will map the sound field in three‑dimensional space.

If the results stay promising, an industry partner could bolt a spiral onto a quadcopter for outdoor trials under current Part 107 rules. City officials watching Amazon’s recent delivery setbacks know neighbors care more about noise than novelty.

Leonardo da Vinci never flew, yet his spiral might help future drones coexist with people and birds in crowded skies.

The study is published in the journal arXiv.

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