Lift modeling, load and vibration analysis of Magnus rotors

Abstract

The method of theoretical combined with numerical simulation is employed to study the lift model and the optimal position of viscoelastic supports for the rotating cylindrical sail (short for Magnus rotor or rotor sail). Initially, using a numerical simulation method to modify the Magnus rotor lift model established based on the Kutta-Joukowski theory obtained a lift/drag model for the rotor. Subsequently, the lift/drag model is utilized as an external load, considering the rotor as a rotating cantilever beam with fixed support at one end. The finite element method is employed to study the vibration characteristics of the drive shaft under external excitation, analyzing the deflection characteristics of the cantilever beam, the stiffness of elastic support, and the span variation on the vibration characteristics of the drive shaft for different cross-sectional radii. Finally, for the investigated large-scale Magnus rotor, a modified lift model and the optimal design position for viscoelastic supports and the dimensions of the drive shaft are provided. Simulation results demonstrate that by appropriately adding viscoelastic supports to the structure, the vibrational deflection of the drive shaft's steady-state response can be significantly suppressed.