Four-Quadrant Propeller Modeling : a low-order harmonic approximation

We propose a four-quadrant propeller model suitable for energy-efficient motion planning of autonomous marine vehicles. The model can be used to capture the main features of experimental thrust and torque curves by using a small number of parameters. We explore the connection between the propeller thrust, torque, and efficiency curves and the lift and drag curves of the propeller blades. The model originates from a well-known four-quadrant model, based on a sinusoidal approximation of the propeller curves, nontrivially modified in this paper to account for the typical drop off in the efficiency curve in correspondence to thrust inversion. Connections with the standard first-quadrant open-water model are drawn