Startup promises efficient and ultraquiet eVTOL flights using magnetic levitation technology.

By Jack Daleo

A top-down view of an eVTOL deploying MagLev’s HyperDrive electric propulsion system. [Courtesy: MagLev Aero]

This week at the Paris Air Show, MagLev Aero co-founders and father-and-son duo Rod and Ian Randall debuted their state-of-the-art propulsion system for electric vertical takeoff and landing (eVTOL) aircraft using an unlikely energy source: magnets.

Maglev is shorthand for magnetic levitation, a term that almost sounds made up. But the propulsion system is actually fairly common, frequently deployed to power high-speed trains. MagLev Aero, however, is working to apply it to eVTOL aircraft and has already been issued more than 20 patents for its technology.

The startup’s progress is underpinned by a development partnership with GE Additive’s AddWorks, a consultancy within the automaker’s design and manufacturing arm specializing in 3D printing, announced Tuesday.

“I’m thrilled to reveal the breakthrough propulsion technology we have been working so diligently and passionately on for the past few years in stealth,” said Ian Randall, the startup’s CEO. “Our proprietary MagLev HyperDrive platform will enable a new generation of eVTOL designs that are dramatically more quiet, efficient, safe, sustainable, and emotionally appealing to the mass market.”

As the younger Randall alluded to, MagLev emerged from stealth just a few weeks ago. Ian, an aerospace engineer, and his father, Rod, a board member at electric vehicle manufacturer Fisker, founded the company in Boston to solve the problem of noise in eVTOL flight—a challenge multiple aviation authorities are also working to address.

To reduce eVTOL noise to a whisper, MagLev is deploying several unique concepts. The most foreign is, of course, a magnetic levitation propulsion system, which in the context of high-speed rail uses magnetic bearings to suspend trains above the track. The system allows the train to “glide” along the rail without creating friction. But in MagLev’s HyperDrive design, those bearings are oriented in a circle within the rotor, which sits beneath a many-bladed rim.

Electric propulsion is distributed evenly and redundantly around the rotor’s perimeter using a combination of magnets and segmented motor control. That enables high hover-lift efficiency while reducing hover noise below that of traditional helicopters and eVTOLs, MagLev said. The redundant orientation also allows HyperDrive to function even after a rotor failure.

MagLev’s many-bladed rim essentially “floats” above the rotor. Its thin, swept blades are more numerous than a typical eVTOL’s, which reduces noise in three key ways: lower tip speed, lower blade loading, and increased load on the outer blade span. Most eVTOL and helicopter designs feature fewer, thicker blades that produce high tip speed and blade loading.

Normally, more blades provide greater lift at the expense of increased power and blade loading. But according to MagLev, HyperDrive concentrates the load on the outer blade span, which actually reduces blade loading and tip speed due to the rim’s high number of blades.

In fact, despite the design’s thin blades, MagLev claims HyperDrive can achieve the same lift as a conventional eVTOL with significantly lower tip speed and revolutions per minute (RPM)—which dramatically reduces noise.

Importantly, though, MagLev is not building its own eVTOL. Rather, it plans to sell HyperDrive to an OEM that is looking to experiment with novel technology.

“We believe our HyperDrive innovation applies to a variety of sizes, configurations, and use cases, and we look forward to working with OEMs and other partners to bring our technology to market,” said Rod Randall, MagLev’s chairman.

According to the startup, it’s already in talks with an unspecified number of “major aerospace OEMs.” It has also garnered support from prominent technology investors and industry leaders, including Material Impact, Grit Capital, Moai Capital (all of which are listed as investors on PitchBook), Breakthrough Energy Ventures, and Stage 1 Ventures, among others.

On Tuesday, MagLev also announced a strategic collaboration with GE Additive’s AddWorks, a global team of more than 70 engineers known for working with emerging technology companies—including aviation startups like Boom Supersonic and Eaton Aerospace.

AddWorks’ specialty is additive manufacturing, the industrial production term for 3D printing. It will use that expertise to develop new manufacturing processes and materials for HyperDrive, which should help MagLev refine its design in future iterations.

“This is a major step for MagLev Aero, and we are thrilled to harness the power of GE Additive’s extensive industry experience, cutting-edge metal additive manufacturing techniques, and proven track record of designing and fabricating additive manufactured propulsion components that satisfy the stringent requirements of aerospace certification,” said Ian Randall.

The elder Randall added that the partnership will help HyperDrive “achieve optimal strength and stiffness at the lightest weight” before the technology is rolled out to the masses.

While MagLev’s eVTOL propulsion system is still in development—and likely several years away from commercial deployment—the firm believes it will find a home in both passenger and cargo aircraft.

Source: FLYING