Efficient cruising for swimming and flying animals is dictated by fluid drag [Biophysics and Computational Biology]

Many swimming and flying animals are observed to cruise in a narrow range of Strouhal numbers, where the Strouhal number St=2fA/U is a dimensionless parameter that relates stroke frequency f, amplitude A, and forward speed U. Dolphins, sharks, bony fish, birds, bats, and insects typically cruise in the range 0.2

Source: Proceedings of the National Academy of Sciences - August 7, 2018 Category: Science Authors: Daniel Floryan, Tyler Van Buren, Alexander J. Smits Tags: Physical Sciences Source Type: research