Under deʋelopмent for мore than a decade, the truss-braced wing concept has Ƅeen extensiʋely tested in CFD and at suƄscale in wind tunnels NASA
There will undoubtedly be difficulties. To begin with, these extraordinarily long wings might just not fit in hangars or airport terminals that are already in use. About the demonstrator aircraft, Boeing hasn’t revealed anything, but on the 2019 design, it mentioned employing foldable wings to circumvent this problem on the ground.
And then there’s the fact that the typical airliners’ enormous, thick, lower aspect ratio wings perfectly hollow out a place for their fuel tanks. By keeping the fuel out in the wings, the stress on the engineering where the wings meet the body is reduced because there is a lot of weight out wide, closer to the center of lift. By keeping burning fuel away from the passengers in a crash, it considerably increases safety. And from a purely practical standpoint, it makes room in the cabin for additional lucrative seats. Fuel tanks will probably need to be moved back into the fuselage because the truss-braced design has such thin wings.
While this demonstration won’t be testing any fancy new engines right away, Boeing claims that the high-mounted, braced wings “may someday support sophisticated propulsion systems that are constrained by a lack of underwing room in today’s low-wing airplane layouts.”
And it should go without saying that anything that can let airplanes fly farther on a given amount of energy is especially relevant to attempts to reduce carbon emissions. These designs might undoubtedly make a significant contribution because clean powertrain options such as battery-electric, hydrogen-electric, hydrogen-coмbustion, ammonia, and others are all hampered by lower range statistics than conventional jet fuel power.
The video below shows some of the CFD (Computational Fluid Dynamics) and wind tunnel work that went into this design, including a fairly gnarly-looking flutter simulation that gives us the impression that trains would be a pretty decent alternative.