Dufour Aerospace announced it has received a grant from the Swiss innovation agency Innosuisse to conduct wind tunnel testing for its aEro 3 crewed tilt-wing eVTOL.
Dufour’s head aerodynamicist, Felix Rubin, will lead the wind tunnel test campaign to confirm the aircraft’s aerodynamic behavior through the full flight envelope, including transitions between vertical and forward flight. The project will be supervised by Dufour’s advisors, Prof. Dr. Leonardo Manfriani and Dr. Pierluigi Capone of the Zurich University of Applied Sciences (ZHAW), and supported by the public research university ETH Zurich, which has been working with the company on the development of flight controls.
As Dufour explained in a press release, “The aerodynamic effects during the transition phase between vertical take-off and cruise, and from cruise back to hover, are difficult to fully predict with conventional calculation and simulation methods. This is due to transient aerodynamic phenomena, flow detachments, and propeller slipstream interactions.”
The results of the wind tunnel test campaign will be used to refine the aEro 3’s design, aerodynamic models, and control laws as the company works toward an aircraft that can eventually serve as a “helicopter replacement,” according to chief technology officer Jasmine Kent.
Dufour has previously conducted small-scale wind tunnel tests. More recently, it completed 550 test flights with its unmanned technology demonstrator, including full transitions. Kent told eVTOL.com that while the demonstrator’s wingspan of around four-and-a-half meters is smaller than the over 10-meter wingspan envisioned for the production aircraft, it is large enough to have comparable aerodynamic characteristics, “which is why we chose that size.”
Although the demonstrator is all-electric, Kent said Dufour expects to develop hybrid as well as fully electric versions of its aircraft, “because you’re fairly limited in the energy you can carry with just batteries alone. But with both of these categories — electric and hybrid-electric — efficiency is very important,” she continued.
“So that’s why we think that a tilt-wing concept makes sense, because as soon as you start to enter transition and tilt the wing you’re generating lift from that wing, and you can operate a lot more efficiently with an equivalent amount of energy — battery chemistry or amount of fuel. We will be able to travel further than most other aircraft capable of vertical take-off and landing.”