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Jetoptera VTOL aircraft design features "bladeless fans on steroids"

https://newatlas.com/aircraft/jetopt...ulsion-system/

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- Jetoptera's J-2000 concept is a remarkably different take on the VTOL inter-city aircraft, designed to make use of the company's own unique propulsion system. Much like the bladeless fans popularized by Dyson, there are no spinning blades to be seen on Jetoptera's "fluidic propulsion systems (FPS)." --- As with the Dyson, there are most certainly spinning blades elsewhere in the system. Both devices rely on fluid dynamics to take a relatively small flow of compressed air, and use it to suck a much greater volume of ambient air through at speed. Sir James Dyson does a pretty good job of explaining it here in the context of his fan, which uses a small, quiet impeller to generate pressure around an aerodynamically shaped loop until it exits at high speed through a slit running around the ring.

- The air is forced back over a wing-shaped surface all around the ring, where it develops the same kind of negative pressure that gives aircraft their lift. In this case, though, any lift is canceled out by equal negative pressure zones all around the ring, and the net effect is a low-pressure vortex in the center of the ring that pulls ambient air through at a great rate. --- Add to that the weirdness of fluid entrainment – the vortices that develop where the cylinder of accelerated air leaving the ring interacts with the stationary ambient air around it – and these designs can end up sucking through 15 times the volume of air initially fed through the ring by the compressor. --- According to the company, this kind of system "improves propulsive efficiency by more than 10 percent while lowering fuel consumption by more than 50 percent compared to small turbojets.

- It's also very light and easy to tilt, allowing VTOL lift and hover operations as well as rapid forward cruise flight. And, unlike virtually any other aircraft propulsion system, it doesn't have to be round. These things can take all sorts of shapes, but most interesting are the long, flat ones that follow the shape of the aircraft's wing. Accelerating air back directly over the full width of the wing can develop significant extra lift, and this allows Jetoptera to design box-winged airframes that take up much less space on a vertipad than most transitioning lift/cruise eVTOLs or traditional helicopters. --- They're relatively easy to stow, and the J-2000 renders show an aircraft that can retract its front two thrusters once it reaches high-speed cruise, to reduce drag and ditch additional unnecessary lift.

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