With its pair of jet engines riding on top, it looks like an airplane that has its wings bolted on upside down. But this innovative 1/11th-scale model recently tested by NASA in a California wind tunnel might represent the future of commercial aviation. Nicknamed AMELIA (Advanced Model for Extreme Lift and Improved Aeroacoustics), the 2,500-pound aluminum and steel model was meant to test, for the first time together, three aircraft design features that usually cause conflicts with each other.
"We know we can do short take-off and landing. We know we can do cruise efficient aircraft. And we know ways to reduce aircraft noise. The question was can we do all three at the same time?" said Michael Rogers, NASA's technical lead for the Efficient Aerodynamic Subproject at the Ames Research Center in California.
Airplanes designed to take off and land in shorter distances usually have more powerful engines, which are noisy, or wing shapes that make them ideal for creating a lot of lift, but not for efficiently cruising at altitude without sacrificing speed or fuel.
On the other hand, wings designed to allow an aircraft to fly efficiently through the air – at high speed and with less resistance – usually require longer runways for take-offs and landings, which would prevent them from being able to fly into and out of smaller airports that have shorter runways.
Measurements of the air flow and noise taken during the wind tunnel tests seem to hint that AMELIA's design does offer a potential solution, but the test's true value is that information gathered with the model will help engineers craft new airplanes in the future.
AMELIA was designed as a 100-passenger, regional airliner that we might see in the 2025 or so timeframe. Among AMELIA's unique features that were the focus of much attention is something called circulation control. This is where high-pressure air is redirected from the jet engines and released through tiny slots that run most of the length of the wing's front and back edges.
As the expelled air passes over the wing and the flaps it creates extra lift through its interaction with the air already moving over the wing that is created by the airplane's forward momentum.
