“NASA asked the world’s top aircraft engineers to solve the hardest problem in commercial aviation: how to fly cleaner, quieter and using less fuel. The prototypes they imagined may set a new standard for the next two decades of flight.”

BOX WING JET, LOCKHEED MARTIN
Target Date: 2025
Passenger jets consume a lot of fuel. A Boeing 747 burns five gallons of it every nautical mile, and as the price of that fuel rises, so do fares. Lockheed Martin engineers developed their Box Wing concept to find new ways to reduce fuel burn without abandoning the basic shape of current aircraft. Adapting the lightweight materials found in the F-22 and F-35 fighter jets, they designed a looped-wing configuration that would increase the lift-to-drag ratio by 16 percent, making it possible to fly farther using less fuel while still fitting into airport gates.
They also ditched conventional turbofan engines in favor of two ultrahigh-bypass turbofan engines. Like all turbofans, they generate thrust by pulling air through a fan on the front of the engine and by burning a fuel-air mixture in the engine’s core. With fans 40 percent wider than those used now, the Box Wing’s engines bypass the core at several times the rate of current engines. At subsonic speeds, this arrangement improves efficiency by 22 percent. Add to that the fuel-saving boost of the box-wing configuration, and the plane is 50 percent more efficient than the average airliner. The additional wing lift also lets pilots make steeper descents over populated areas while running the engines at lower power. Those changes could reduce noise by 35 decibels and shorten approaches by up to 50 percent.—Andrew Rosenblum

Source: Rosenblum, Andrew. “Jet Setters” Popular Science May 2012