A Four-Quadrant Thrust Estimation Scheme Based on Chebyshev Fit and Experiment of Ship Model

This paper proposes a thrust estimation scheme for marine propellers in four-quadrant operations. To calculate the thrust and torque coefficients of screw propeller in four-quadrant, a Chebyshev fit expression of the propeller properties in four-quadrant for surface vessel is given, and then it is changed into an ordinary polynomial expression. These expressions are suitable for calculating the value of the propeller thrust and convenient for studying the ship’s maneuverability. On the basis of ship-propeller movement characteristics, the dynamical models of propeller in fourquadrant operations are given. The effectiveness of the proposed thrust estimation scheme is validated by experimental results derived from an electrically driven fixed pitch propeller, which provides a good reference for the vessel operations.