Tuning of Strouhal number for high propulsive efficiency accurately predicts how wingbeat frequency and stroke amplitude relate and scale with size and flight speed in birds.

@article{Nudds2004TuningOS,
  title={Tuning of Strouhal number for high propulsive efficiency accurately predicts how wingbeat frequency and stroke amplitude relate and scale with size and flight speed in birds.},
  author={Robert L Nudds and Graham K. Taylor and Adrian Lloyd Thomas},
  journal={Proceedings. Biological sciences},
  year={2004},
  volume={271 1552},
  pages={2071-6}
}
The wing kinematics of birds vary systematically with body size, but we still, after several decades of research, lack a clear mechanistic understanding of the aerodynamic selection pressures that shape them. Swimming and flying animals have recently been shown to cruise at Strouhal numbers (St) corresponding to a regime of vortex growth and shedding in… CONTINUE READING