Planes designed to look like birds would be more aerodynamic than traditional shapes, say a pair of engineers in California and South Africa.
Geoffrey Spedding, an engineer at the University of Southern California and Joachim Huyssen at Northwest University made a simple modular aircraft in three configurations: a flying wing alone, wings plus body and wings plus body and a tail.
They analyzed the airflows at various relative angles for the wings, body and tail, searching for ways to achieve greater lift - the better for carrying cargo - and lower drag, for higher fuel efficiency. They made the stipulation that for any given mission, the best plane would be the one that generated the least drag.
The flying wing alone provided an ideal - if rather impractical - baseline. As soon as a body was added, lift was decreased and drag rose. But the engineers found that the addition of just the right kind of tail could restore the lift; it also reduced drag, at times to nearly wing-only levels.
A few years ago a glider with the modest tail design was successfully test flown, but larger and commercial test prototypes haven't yet been tried. Spedding and Huyssen say they recognize that the design of real planes is necessarily a compromise, but believe much can be done to make planes more energy efficient in the future.
"The most important point is that we may be wasting large amounts of fossil fuel by flying in fundamentally sub-optimal aircraft designs," says Spedding.
"At the very least, we can show that there exists an alternative design that is aerodynamically superior. One may argue that there is now an imperative to further explore this (and perhaps other) designs that could make a significant difference to our global energy consumption patterns."