kitesh wrote:Forgive me if this has been asked, but I didn't see such a clarification listed.
I am in a division where rotors are defined as "surfaces that contribute lift by rotating on a common path around a vertical axis. The helicopter may use up to three fixed pitch rotors, not exceeding a maximum diameter of 35.0 cm."
Does 'Fixed Pitch' mean:
1. Pitch does not change during flight
2. The pitch (Angle of the chord) is constant across the radius of the rotor
# 2. would seem to outlaw many of the interesting designs, like helical or elliptical (optimized) rotors.
This is not the place for official clarifications, but generally within our terminology fixed pitch is the opposite of variable pitch, which is a technique (detailed here: http://indoorduration.com/ftp/VPPropConstruction.pdf ) that allows the pitch of the rotor (or propeller) to change throughout the flight dependent on the torque for the rubber band.