AAM Industry Gets a New (Electric Ducted) Fan

However, this fan, which comes from German propulsion developer Schubeler Technologies, is of the electric ducted variety. The eP05-21, unveiled Tuesday, is the company’s latest product. But unlike the rest of its catalog, which is primarily geared toward the sport and hobbyist industries, the new design is built for the AAM industry.

According to Schubeler, the eP05-21 is “designed specifically to power both manned and unmanned eVTOL aircrafts.” The fan is the first in a new line of aerospace-specific products under the banner Schubeler Aero. High static thrust fans, motors, propellers, and compressor drives are also listed as Aero offerings on the company’s website.

“It’s tested and proven technology. We’ve completed intense wind tunnel testing in July as well as successful integration in actual eVTOL aircraft,” said Daniel Schubeler, the firm’s founder and chief technology officer.

Already, Schubeler Aero counts major eVTOL manufacturers Lilium and Volocopter, both based in Germany, as customers. In May, the former equipped its aircraft with Schubeler fans for wind tunnel testing.

The firm is also working with AAM companies Bellwether and Tupan as well as Airbus, which is developing the CityAirbus eVTOL, and Boeing, which owns eVTOL air taxi operator Wisk Aero. General Atomics, a manufacturer of unmanned aircraft for defense, is listed as another customer.

With a diameter just more than 20 inches and a weight of 18.2 pounds, the eP05-21 is built for larger AAM aircraft. It uses a 21-kilowatt DC power input to produce 680 newtons of static thrust—that means it can accelerate an object with a mass of 680 kilograms by 1 meter per second squared. It achieves between 4,900 and 5,700 revolutions per minute.

The fan’s sub-60-volt architecture makes it a low voltage option that the company says is primed to be integrated into eVTOL aircraft. It operates within a flight speed range between 0 and 148 feet per second.

The eP05-21 is designed to be certificated under the European Union Aviation Safety Agency’s (EASA) SC E-19 framework for electric and hybrid propulsion systems as well as the Radio Technical Commission for Aeronautics’ DO-160G category for testing airborne equipment.

Known as a manufacturer of electric propulsion systems since 1997, Schubeler actually got its start building electric, carbon fiber-reinforced polymer axial fans for the sport and hobby sectors. However, in 2021 it was approached by a large AAM customer to create the electric propulsion systems for its eVTOL demonstrator.

Shortly after, the company began developing its first aero electric ducted fan, which it now hopes to integrate into a growing number of eVTOL aircraft designs.

Other firms, such as Honeywell and Nidec Aerospace, also design and build systems to be installed on other companies’ AAM aircraft. But Schubeler isn’t the only one hoping to sell fans.

Another company, Whisper Aero, is also developing electric ducted fans for eVTOL and electric aircraft. The firm’s “ultraquiet” design combines low propeller tip speed with an ultrasonic blade passage frequency—inaudible to the human ear—to reduce noise to, well, a whisper. It claims to be able to do so while also delivering 20 percent greater efficiency compared to other ducted fans.

For what it’s worth, Schubeler’s eP05-21 is expected to produce 61 dBA of noise at a distance close to 400 feet during flyby. That’s about the same volume as a conversation between the folks sitting one table over from you at a restaurant.

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