Ever since I tried to fly rubber powered models as a kid, I have had a keen interest in propellers. The model aircraft hobby deserves its own section.
TODO Refer to "model aircraft" for the criminal quality of the "Veron" kits, and with the likes of AeroModeller. The "Veron" kits contained rock hard balsa, a nice but far too small propeller, and a much too thick, half dried out loop of rubber. Th plans hanbook, the dihedral explanation, the later own designs, the "voodoo" aspect, scale speeds, bicycles and small rooms, calm evenings and long grass. Village green, Cardington sheds, All Scale Day, Czech republic. Round the pole, yearly trade fair. Scheijde, the thief. Jodel Ambassadeur, bendable pins. Gliders A1, A2, indoor models. I wanted scale models. No way I could start diesels.
In my second year in Delft, I followed the mesmerizing lectures of prof. Dobbinga on the aerodynamics of propellers. In retrospect, they were good Dutch translations and re-interprations of Glauert's classic treatment in Durand. Sadly, in the Delft curriculum it was not the habit to let students use the original literature.
I tried to apply Dobbinga's theory to my rubber models, but frankly they still did not perform the way I hoped, and I left the subject for a few decades.
Years later, in a second-hand book stall at an airshow on Old Warden aerodrome I found a loose binder with a photocopy of a hand written propeller code by Eugene Larrabee.
Around the same time "Scientific American" carried an article by Larrabee on the vast increase in performance of a paddle-shaped propeller over straight blades in the "Gossamer Condor" man-powered aircraft. It made the difference between a flight of 1 mile maximum and a flight from Crete to Santorini.
I tried my hand at implementing Larrabee's code, which was very similar to Dobbinga's lectures.
The code implemented classical propeller design in what turned out to be Adkins's version of Larrabee's version of Glauert's version in Durand of Betz's method from 1919.
I programmed the algorithm, first on Texas TI-58 calculators ( typing the inputs by hand, and plotting the data in pencil and Rotring ink on orange millimeter graph paper ), then on a Sharp MZ-700 MSX home computer which had three tiny color ball points plotting onto a tiny roll of paper, and finally on the early Microsoft PC's in Matlab. After that, life got in the way.
Recently, my interest was rekindled by a project at InHolland University in Delft to electrify a Dragonfly canard aircraft. Although I did not like the choice of aircraft, the project gave me the push to try my hand at writing a simple, introductory student textbook for InHolland on propeller theory.
The introductory textbook project got a bit out of hand.
As the book progressed, some new theory found its way into it. The book has sections on viscous optimization and on the exact solution for the tip loss which are not normally found in the known texts on classical propeller theory.