Simple scaling law predicts peak efficiency in oscillatory propulsion [Engineering]

Oscillatory propulsion is ubiquitous among swimming and flying animals, and may some day be practical as a replacement for rotary propulsion in watercraft and small air vehicles. The strength and efficiency of flapping thrust production closely depend on a dimensionless parameter called the Strouhal number (St), representing the ratio of...

https://ift.tt/2niAwQr