NASA has successfully demonstrated a manufacturing technique that will allow the creation of large, commercial hybrid flying wing aircraft. These planes would use half the fuel of conventional, tubular jet airliners, and would provide a quieter ride for passengers on board.
In general, there are four plane shapes: A tube with wings, a blended wing body, a hybrid wing, and a flying wing. The last three ditch the tube in favor of a much flatter chassis with an almost-rectangular cross-section. The advantage of these designs is that the body actually acts like a wing, adding extra lift. The down side is that flying wings are less stable (they lack a tail), and the rectangular cross-section makes it a lot harder to build a light fuselage that can withstand the rigors of pressurized air flight.
Aerospace engineers have long been aware of the advantages of flying wing aircraft — reduced weight, and drag, and thus higher top speeds and lower fuel consumption — but it has so far proved impossible to build a flying wing that’s large enough to transport hundreds of people in comfort. There are dozens of flying wing designs in use by the military, but these are generally small aircraft that don’t need to worry about the comfort of the soldiers on board. The Northrop Grumman B-2 Spirit (Stealth Bomber, pictured above) is probably the best-known example of a hybrid flying wing aircraft.Now, NASA is reporting that it has devised a manufacturing method of producing hybrid flying wing aircraft that is large enough for commercial travel. The method starts with carbon composite rods, which are then covered with carbon fiber fabric. Foam strips are placed between the rods, and again carbon fiber is stitched onto them, creating structural crossmembers. The carbon fiber fabric is finally impregnated with an epoxy resin, turning the whole thing into a very rigid structure when it sets. All told, this new technique can reduce the weight of an aircraft’s structure by 25%.
In testing, fuselage parts made using this technique could withstand the necessary forces. The plan now is to build a 30-foot (9.1m), two-floor fuselage to see how the new manufacturing technique copes in situations that approximate real-world use. Eventually, 10 or 20 years down the line, NASA hopes that this manufacturing technique can be used to build commercial jets.
As Technology Review points out, a hybrid flying wing aircraft would also need a different kind of engine — something like an ultra-high-bypass engine. Ultra-high-bypass engines (aka propfans or unducted fans, pictured right) still use a “turbo” design, but have a large number of small, twisted propeller blades at the back — kind of like if you took a turbofan, but removed the housing from the back half of the engine. In NASA’s hybrid flying wing, these UHB engines would be mounted on top of the plane, reducing the noise inside the fuselage).
This hybrid flying wing is just one facet of NASA’s Environmentally Responsible Aviation (ERA) project, which was instigated in 2009 with the hope of reducing the impact of aviation on the environment. For more information, hit up the NASA website.
