SEOUL, Sept. 10 (UPI) — Researchers in South Korea say a study of flying fish aerodynamics shows them ideally suited to both flying and swimming.
Flying fish can remain airborne for more than 40 seconds, covering distances of almost 500 yards at speeds of 40 mph.
Haecheon Choi, a mechanical engineer from Seoul National University, South Korea, decided to find out how these unexpected fliers stay aloft and published the discovery that flying fish glide as well as birds in The Journal of Experimental Biology.
By mounting stuffed fish with their fins extended in a wind tunnel Choi and his colleague Hyungamin Park tested their aerodynamics.
Calculating the fish’s lift-to-drag ratios — a measure of the horizontal distance traveled relative to the descent in height during a glide — Choi and Park found that the flying fish performed remarkably well, gliding better than insects and as well as some birds.
They also found that the fish were very stable as they glided. However, when they analyzed the stability of the fish with its fins swept back in the swimming position it was unstable, exactly what is needed for aquatic maneuverability.
So flying fish are superbly adapted for life in both environments, Choi and Park determined.
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