Tennesse-based startup's new technology will help silence flying taxis

In 2021, Mark Moore and Ian Villa, colleagues at Uber Elevate, co-founded Whisper Aero to bring about a silent revolution in electric propulsion and make noiseless flight a reality. Eight months later, the startup flew a drone propelled by its noiseless technology and has now unveiled the technology that makes it work.

Silent electric propulsion

At the core of Whisper Aero's ultra-quiet electric jet is a propulsion disc, In plain speak, it is a fan with a very high number of blades joined together with a shrouding ring. The diameter of the disc is small to ensure that the speed of the blade tip remains low, as the revolutions ramp up to enable flight.

The idea behind putting in a large number of blades is to push the blade passage frequency beyond 16,000 Hertz and outside the range of human hearing. So, even though the engines make noise, it is inaudible to the human ear and even to that of a dog, claims the company.

Since the design incorporates many blades, the propulsion disc can be spun much slower than a propeller blade on an aircraft. The shrouding rim also ensures there are no gaps between the blade tips and duct housing, further reducing the possibility of noise being generated.

A six-inch propulsion disc tested by the company is audible from 200 feet (61 meters). Ducted fans and propellers with similar thrust generated up to 52 dBA and 59 dBA, respectively, as against the 34 dBA of Whisper's tech.

The route ahead

Given the small size of its propulsion disc, Whisper needs to put a lot of them together to generate the necessary lift for an aircraft. The result is a bit of an odd-looking airplane, but this isn't affecting the company's confidence in its capabilities.

The aircraft, designed to take off and land conventionally, can seat nine passengers and a pilot and zoom at 288 miles (463 km) an hour. Fully charged, the aircraft could fly 200 miles (322 km), but the company is also looking at extending this to 500 miles (800 km) using a hybrid system.

For now, Whisper Aero is focused on improving the propulsion design and increasing the diameter of the fan. Instead of designing the entire aircraft, it would also be happy to provide the silent propulsion technology to others and be part of more flying taxis than it can build on its own.