|A propeller behaves as a rotating wing producing lift in the direction of the axis of
rotation. Many previous propeller optimization methods have been developed, but usually
focus on piston or turboprop applications. This study discusses the more fundamental propeller
theories and uses a hybrid blade element momentum theory to model the propellers.
A brushless motor model is developed and coupled with the propeller theory in an optimizer.
Two single point optimizations are made, one for a climb condition and the other
for a cruise condition. A third optimization is presented with optimization at climb and
cruise conditions. The optimizations are conducted with a hybrid pattern/search particle
swarm optimizer. The airfoils for the propellers are optimized with the same optimizer and
a simplex method. Multiple objective functions are evaluated for each of the conditions.
One having non-dimensional values and another with dimensional values. Dimensional values
prove to provide better results for all of the conditions. The optimized cruise propellers
display smaller chords, higher pitches, and larger diameters while the optimized climb propellers
have larger chords, lower pitches and smaller diameters. The multipoint optimization
yields higher pitches with chords and diameters between the single point optimizations. All
optimized propellers show improvement over comparable baseline propellers.