Supplementary Information for: Propeller efficiency and the spectrum of propulsor form with speed, from pike to tuna, vulture to swift.

Notes for Supplementary Information relating to

Usherwood, J.R. (in press / 2025). Propeller efficiency and the spectrum of propulsor form with speed, from pike to tuna, vulture to swift. J. R. Soc Interface.

The original code for Figure 2 plots was developed in National Instruments LabVIEW (2023): the .vi ‘GetSurface.vi’ calls ‘UnderlayerPowerMatch.vi’, which calls ‘UnderlayerPropellerMaths.vi’.

An alternative in Python is provided as ‘propeff_Ush2025.py’. This version was coded by Simon Wilshin.

Further explanation and animated parameter sweeps are available at https://jimusherwoodresearch.com/wings-and-fins/