UFOs may soon no longer be just the realm of science fiction writers: researchers at the Delft University of Technology in the Netherlands have started working on an "ultra eco-friendly plane" of the future which, in the vision of project director Etnel Straatsma, happens to be a flying saucer. As the head of recently-started CleanEra project, he hopes to design a plane that will reduce noise and release 50% less carbon dioxide per passenger-mile than current airliners.
According to Alexander de Haan, also of Delft University but not affiliated with the project, the main challenge will be overcoming the already close to maximally optimized airplane technologies. After examining several possible design modifications and improvements, he estimates that, at most, they could reduce carbon emissions by up to 15%. "These ideas cannot keep up with the 5 percent growth that the [airline] industry continues to have year after year," he explained.Straatsma and his colleagues are currently considering a range of possible options — a return to propellers, composite materials, ergonomics and biofuels — to help them reach their ambitious goal. Though more fuel efficient than jets, Straatsma has been lukewarm about the merits of propeller-driven planes, citing comfort as a serious concern: ""One of my requirements is to increase comfort, and we can't do that by making flights longer." However, she says that placing two propellers in a row with oppositely turning blades to reduce noise could be a possibility.
Another option would be to switch to composite materials (plastic reinforced by woven fibers) for the plane's fuselage — a modification that would weigh less, improve aerodynamics and thus reduce fuel consumption. Such a design could help the plane "reach a 30% weight reduction," according to de Haan. Biofuels, another cited alternative, would help reduce total carbon emissions though there are some worries that higher biofuel blends could freeze at sub-zero temperatures in high altitudes. Hydrogen fuel, which eschews that problem, might help once the technology to store it in small gas tanks is achieved.
The last, and perhaps most obvious option, would simply be to place more passengers on each plane. A "blended wing" body could accommodate up to 800 passengers by seating some out into the wings. The only problem would be that those sitting further away from the plane's central axis would likely experience a more "turbulent" ride. Also, airlines would have to review the feasibility and necessity of having planes with such large capacities.
While promising, de Haan cautions that such modifications may well take decades before they are fully implemented. We'll be keeping our fingers crossed.