Flight physics

How do birds fly and how does an aircraft lift-off? Image: DLR/K.-A.
How do birds fly and how does an aircraft lift-off? Image: DLR/K.-A.
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To be able to fly is one of mankind's oldest dreams. In the course of the last century it became a reality, and today flying is a matter of course. We go on vacation by plane, and flying kites or sailplanes and paragliding are leisure activities. Despite such achievements we have not completely conquered nature, however. For example, we cannot fly using only our strength, as birds do. Other puzzles of flight have not yet been completely resolved, such as the complex wing motion of those true flight experts, the dragonflies, something which still poses challenges to our understanding.

Flight - mankind's dream

"All flight depends on creating air resistance, and all of flying consists in overcoming air resistance", Otto Lilienthal (1848-1896). This insight, seemingly obvious to us, was revolutionary over a hundred years ago. The engineer and flight pioneer Otto Lilienthal devoted many years of his life to unpuzzling the mystery of flight. Only when equipped with this knowledge were engineers able to distribute the two functions of a bird's wing between two sets of aircraft components: stiff, curved wings to generate lift, and propellers or jet engines to produce the necessary propulsive thrust. This basic principle has remained unchanged since the inception of aviation. But in recent years the archetype of a bird's wing has again caught the attention of aircraft constructors. DLR and the aviation industry are working together to design the wings of future commercial aircraft.

Going around in circles

In order to understand the fundamentals of flight, you'll experiment at DLR_School_Lab using a rotating test stand (which we sometimes casually refer to as our merry-go-round). Flight phenomena will be vividly demonstrated and you can then investigate them systematically. You can fasten various aircraft models to this rig and then measure lift and air resistance at different velocities and angles of pitch. The wing motion of an artificial bird will give you some insights into how flying animals generate needed thrust.