The role of propeller aerodynamics in the model of a quadrotor UAV

We study models of a quadrotor UAV. These models include various aerodynamic effects of the propellers and their interactions with the motion of the rigid body of the UAV. Two main assumptions are formulated: the twisting of the propellers is such that the local angle of attack is constant along the blades in stationary flight, and, secondly, that the local induced velocity is also constant along the blades. Under these assumptions (which correspond to an optimal hovering rotor), we conclude that the flexibility of the propellers plays an important role in the dynamics of the UAV (including the effects of the vertical location of the center of gravity), and that it is interesting to account for it when designing a closed loop controller.