Whisper Aero, a pioneering company in electric aircraft propulsion systems, has recently unveiled an extraordinary breakthrough in aviation technology. Their innovative Whisper Jet concept promises to deliver unparalleled levels of noise reduction and efficiency. By producing less than 50 decibels of noise when flying at a mere 500 feet altitude, these electric jets have the potential to transform urban air travel. With their electric aircraft propulsion systems claimed to be “20% more efficient and 100 times quieter than anything else on the market,” Whisper Aero is set to redefine the standards of electric aviation.
The Propulsion System:
At the heart of the Whisper propulsion unit lies a remarkable component known as the “propulsion disc.” This fan-like structure is equipped with an unusually large number of strong and rigid blades, reinforced by an outer shrouding ring for added strength. The design ensures a small diameter fan, allowing for lower blade tip speeds at the relevant RPMs during flight. With its multitude of blades, the “blade passage frequency” surpasses 16,000 Hz, rendering it beyond the range of human hearing. Remarkably, even dogs in close proximity to the fan tests remained unaffected, as confirmed by Whisper’s co-founder and CEO, Mark Moore, who brings his extensive experience from NASA and Uber Elevate.
The advantages of utilizing numerous blades extend beyond noise reduction. The Whisper propulsion system can rotate at significantly slower speeds compared to traditional propellers or turbofans. This lower rotational speed minimizes the centrifugal forces exerted on the rim, ensuring structural integrity. Furthermore, the shrouding rim effectively eliminates the gap between the blade tips and the duct housing, thereby further reducing blade tip vortex noise.
Whisper Aero emphasizes that any energy lost to noise is energy not converted into thrust. The company boasts rotor efficiencies of up to 92%, even with fan diameters as small as 6 inches (15 cm). These impressive efficiency levels demonstrate the potential of the Whisper propulsion system to maximize the performance of electric aircraft.
In comprehensive acoustic testing, a 6-inch Whisper fan was found to be completely inaudible from 200 feet (61 m) away, amidst a background noise floor of 30 decibels. The fan was compared against two ducted fans and two open propellers, which were acknowledged as the quietest commercially available products. All configurations produced the same 7.8 lbf (34.7 N) of thrust. At a distance of 100 feet (30.5 m), the Whisper fan recorded an astonishingly low noise level of 34.1 dBA, while the ducted fans measured 44.9 and 52.1 dBA, and the open propellers measured 49.4 and 58.7 dBA. The substantial difference in noise levels attests to the Whisper propulsor’s superiority, offering a noise reduction of 100-500 times compared to ducted fans, and 100-1,000 times compared to open propellers.
Whisper Aero’s recent unveiling of their ultra-quiet and highly efficient electric ducted jet marks a significant milestone in electric aviation. While the company’s primary focus lies in developing and commercializing the propulsion system, they have also showcased the Whisper Jet concept—a visually distinctive aircraft featuring Blohm and Voss Outboard Horizontal Tail (OHT) configuration reminiscent of Virgin Galactic’s VSS Unity. The Whisper Jet, capable of carrying a pilot and nine passengers, demonstrates the potential for 200-mile (322 km) electric-powered journeys at speeds of up to 288 mph (463 km/h), utilizing conventional runway takeoff and landing (CTOL) methods. By incorporating hybrid systems, the aircraft’s range could be extended to approximately 500 miles (800 km).
Whisper Aero envisions their propulsion system being utilized in short takeoff and landing (STOL) aircraft, drones of various sizes, and potentially, in the future, eVTOL air taxis. The company is actively exploring different fan diameters, including options such as 4 inches, 10 inches, and a specialized 24-inch version designed for integration with the AFWERX High Speed VTOL program, where it will compete with other groundbreaking propulsion technologies.
The integration of low noise and high efficiency into electric aircraft represents a remarkable advancement in the field of aviation. As Whisper Aero’s revolutionary propulsion units enter real-world applications, it will be intriguing to witness their performance and witness which clients embrace this groundbreaking technology to shape the future of electric aviation.
Source : Whisper Aero