Whisper Aero Supercomputes and Grows

Supercomputing to Quiet Aerodynamics

Whisper Aero of Crossville, Tennessee supercomputes its way to grand new designs.  Affiliating with the Oak Ridge National Laboratory (ORNL), the powerplant designer and manufacturer uses the Lab’s supercomputer to investigate the most desirable aerodynamic approaches.  The ORNL is working with Whisper on a nine-passenger electric airplane called the Whisper Jet.  The collaborators will employ the world’s fourth fastest supercomputer, Summit.  (It was the fastest until recently).  According to ORNL, access to Summit and its graphics processing unit (GPU) architecture gives Whisper Aero’s team a tenfold speedup over Whisper’s in-house CPU (Central Processing Unit)-only systems.  It enables advanced simulations compared to previous systems.

Whisper Aero gets time on ORNL’s Summit Supercomputer to perform complex calculation and simulations

Vineet Ahuja, Whisper Aero’s Head of Flight Sciences and an Associate Fellow at the American Institute of Aeronautics and Astronautics, says, “Using Summit affords us the possibility of expanding the scope of Whisper’s design and analysis activities that benefits aircraft control and aeropropulsive integration,  As a result, aerodynamic design has shown an incredible turnaround time relative to where we were just a few years back in our pre-Summit days. This speedup ultimately benefits vehicle development cycle times, which are reduced by over 20 percent.”

 While Whisper Aero engineers and designers are using the Summit for work on the nine-seat craft, several other projects are keeping the company busy.

The Single-Seat Sailplane

Whisper acquired a Belgian Swift flying wing sailplane , originally designed by Ilan Kroo of Stanford University several decades ago.  On this, they have mounted an eQ160 electric ducted fan propulsor that generates about 70 pound’s of thrust.

Whisper Aero is modifying a Swift flying wing sailplane with a Q250 ducted fan propulsor

This type of ultralight sailplane is flying worldwide with Eck-Geiger electric motors in the 12 to 20 kilowatt range.  It will be interesting to see some head-to-head comparisons between those craft and Whisper’s test craft.  The Q250 propulsor is  designed to power small people-carrying aircraft in the Group 3 drone range.

The Nine-Seat Regional Airliner

Whisper’s current main project is a nine-seat regional airliner that can operate out of 3,000 foot airstrips.  As Mark Moore points out, his previous work with Uber Elevate was for urban air mobility , while the Whisper design can fly from existing regional airport, connecting cities and towns with smaller populations.  Several benefits accrue: less need for long lines through TSA checkpoints, more convenient loading and unloading on the aircraft, and more accessible points of departure and arrival.

Dr. Mark Moore (in tan jacket) with members of his Whisper Aero crew with the mockup of their nine-passenger regional airliner.  Note multiple propulsors on the wing’s leading edge, helping to add lift and promote short-field performance.

From a design standpoint, the nine-seat regional craft share many design elements of the 100-seat airliner.  In fact, the basic outline of every Whisper design echoes a similar concept.  Distributed electric fans blow across the leading edge of a long wing, tail surfaces are offset and trailing on a slender offset structure.  This type of aerodynamic and structural creativity requires the best of engineering and computation to make into a dynamic reality.

The 100-Seat Airliner

Yves Le Marquand, writing for Revolution Aero News explains “Whisper Aero has unveiled a 100-seater commercial aircraft concept it calls Whisper Jetliner at the Ohio Air Mobility Symposium.”  CEO Mark Moore notes the large craft employs larger versions of the firm’s “electric ducted fans integrated into a wing to achieve Upper Surface Blowing, as pioneered by the NASA QSRA flight demonstrator.”  The craft would be part of a proposal Whisper has submitted to NASA’s Advanced Aircraft for Sustainable Aviation project, slated to “provide a path toward net-zero aviation emissions by 2050.”

NASA’s QSRA (Quiet Short-Haul Research Aircraft) was a predecessor to the Whisper Jet Airliner

Whisper’s Jetliner has a 27-percent thrust-to-weight ratio, which will allow battery electric (in conjunction with a 4 megawatt series hybrid) ranges of up to 769 miles on IFR (instrument Flight Rules), which require higher reserves).

The concept also feature an outboard horizontal tail configuration. This helps to improve aerodynamics, lower noise across the board and shorten takeoff and landing field lengths to under 3000 ft.

Whisper Aero’s 100-passenger Jetliner follows basic design philosophy of most Whisper platforms

On top of that, integrating Whisper’s electric ducted fans along the leading edge of the wing increases the aircraft’s wing loading by over 20 percent. This in turn increases the cruise high speed lift-to-drag ratio from 17.5 to 22. All of that decreases energy use, and subsequently, direct operating cost.

Moore explains, “Ultimately, achieving sustainability is about the ability to outcompete existing hydrocarbon-based alternatives on operating costs, which would force early retirement of existing fleets.”

According to Whisper, energy costs for a typical 500 mile trip are $733 for the Whisper Jetliner (at an industrial electricity rate of $.07 kilowatt hour) compared to $2,100 (at a fuel price of $2.00/gallon) for an equivalently sized current commercial aircraft, such as an Airbus A320-100.

Propulsors

Whisper Aero is developing a series of ducted fan propulsors following their quiet design philosophy.  Currently, they range from five pound-feet of thrust to 70 pound-feet.  The company will work with clients to craft bespoke units.  The firm seeks out air-framers to build their aircraft design, preferring to concentrate on propulsors.  It will exciting to see their ideas come to fruition, including commercial applications such as their ultra-quiet leaf blower.  Neighborhoods around the world will bless the silence, either in the neighbor’s yard or at the neighboring regional airpark.