Performance of a Magnus effect-based cylindrical roll stabilizer on a full-scale Motor-yacht

The rotor stabilizer systems based on the Magnus principle are among the alternative systems used as an antirolling system. The key objective of this paper is to extensively study the performance of the Magnus stabilizer on a ship's roll-heave motions in a regular beam sea and at low velocity, as well as to investigate the hydrodynamic characteristics of the rotating cylinder in the varied diameters and rotation speeds. Two-dimensional rotating cylinders and three-dimensional ship-rotor cases are simulated using the RANS solver by adopting SST k. turbulence model. Flow past a rotating cylinder is computed with cylinder diameter-based Reynolds Numbers of 7.33 x 10(5), 1.01 x 10(6) and 1.26 x 10(6) in the spin ratio range of 1.52 < alpha < 13.09. The rotational motion of the cylinder is simulated by the rotating wall approach. The lift forces obtained from two-dimensional analyses are applied externally as damping moments to examine the effect of Magnus stabilizer on the dynamic motions of the full-scale motor yacht. The results indicate that the increased diameter is effective on the lift force than increased rotation speed. The ship-rotor interaction is successfully modeled by external moment application as a practical engineering approach. Magnus stabilizer presents a high-performance in roll reduction that varies between 9.13% and 85.84%.