Numerical investigation of variable damping model based on cylinders with different submergence depths

To reduce the blockage effect, a novel arrangement involving a submerged cylinder and a floating cylinder arranged in tandem is studied using two-dimensional RANS equations in conjunction with the SST k-ω turbulence model. The motion of the cylinders is solved using the Newmark-β method. A variable damping method based on movement velocity is proposed to achieve continuity of motion and improve energy harvesting. Results indicate that the variable damping method enhances the motion response, increasing amplitude by 20.832% (submerged cylinder) and 34.764% (floating cylinder). Moreover, the absorbed power of the floating cylinder increases by 9%. Powers and exponent are comparatively linear concerning each other based on energy harvesting: absorbed power increases with increasing exponent when the exponent is smaller than 1, while it decreases with increasing exponent when the exponent is bigger than 1.