... potential simulation codes in order to add viscous damping. What has been shown herein is that a right selection of KC has a larger impact on the models than the uncertainties due to eventual scale effects in the heave-plates dynamics. Email: [email protected] Email: sergio.fernandezruano...

... to the longitudinal axis of the floating body. The HC and wave forces are computed by integrating over the length of the floating body using the strip theory formulation [ 28 ]. The sectional added mass, sectional damping, and sectional wave exciting forces were obtained from the HC based on the experimental results...

... of the VIM is presented such as heading, external appendages of the hull, concomitant presence of waves and currents, motion suppressor, draft condition (immersed portion of the hull), and external damping due to the presence of risers. Previous works concerning the VIM studies on spar and monocolumn...

... the transverse force and motions experienced by an oscillating cylinder in steady flow with lift, added mass, and damping. Thus, steady state responses obtained from the model represent the unique nature of VIV found in the laboratory over a range of reduced velocities of practical importance. The model...

... differential equations comprising nonlinearities associated not only with stiffness and damping but also with inertia terms. A dynamic analysis is performed by subjecting the model to JONSWAP ocean wave spectrum compatible extreme forces (corresponding to the 100 year wave) and to moments applied to the center...

... force on a receding horizon. The wave excitation force is predicted by use of an augmented Kalman filter based on a damped harmonic oscillator model of the wave process. It is shown how constraints influence the optimal motion of the heaving wave-energy converter, and also how close it is possible...

... relations is examined for the porous body. It is found that the damping coefficient consists of two parts. In addition to the component of conventional wave-radiating damping, there exists a second component caused by the porous effects. In addition, the Sommerfeld radiation condition is imposed at far...

...Hamid Zeraatgar; Mohsen Asghari; Firooz Bakhtiari-Nejad In this study, a method for the extraction of damping by tracing free roll decay is presented. For this purpose, in calm waters, a bulk carrier model is given a large initial roll angle and then released. Consequently, the roll motion...

... beam of a FPSO with rectangular geometry. Both free decay and forced oscillation tests were conducted on the range of geometries at different amplitudes and frequencies. The results show that, for given amplitude of roll motion, the damping coefficient increases with increasing bilge keel size up...

...Jeffrey M. Falzarano; Srinivas Vishnubhotla; Sarah E. Juckett In this paper various techniques of dynamical system analysis are used to analyze the effect of damping on large amplitude nonlinear ship-rolling motion of a patrol vessel. In particular steady state magnification curves, Poincare maps...

... damping coefficient, and the distribution of dampers along the height of the structures under various sea states. A four legged steel jacket platform in a water depth of 122 m is considered as an example problem for finding out the controlled responses. Three wave conditions are considered, namely...

... that the cylinder operate in VIV under high damping and as high a Reynolds number as possible. At the same time, a broad range of synchronization is required to make VIVACE effective in energy generation in a realistic environment. Due to these requirements, VIV tests have not been performed before in the subspace...

... such as electricity using VIV successfully and efficiently for the first time. VIVACE is based on the idea of maximizing rather than spoiling vortex shedding and exploiting rather than suppressing VIV. It introduces optimal damping for energy conversion while maintaining VIV over a broad range of vortex shedding...

.... The hydrodynamic behavior of the point absorber depends, to a large extent, on the damping of the generator. The damping, in turn, can be remotely controlled by changing the load resistance. It has previously been shown that this has a large influence on the power absorbed by the wave energy converter. This paper...

... system, with nonlinear damping and restoring terms. FTLEs are numerically calculated at every integration time step. Using this numerical model of parametric roll and through tracking trends in the FTLE time series behavior, warnings of parametric roll are identified. This work serves as a proof...

... and damping ( m * = 1.0 , ζ * = 0.005 ), a reduced velocity of U * = 6.0 , and allow for two degree-of-freedom ( X and Y ) motion. The numerical implementation makes use of overset (Chimera) grids, in a multiple block environment where the workload associated with the blocks is distributed among multiple...

...Nagan Srinivasan; Subrata Chakrabarti; R. Radha An offshore platform that is efficiently designed to reduce the wave excitation forces and increase the separated-flow damping could qualify as a platform operating even near its resonance. Such design could make this concept cost-effective, as well...

...R. Panneer Selvam; S. K. Bhattacharyya Dynamics of a large moored floating body in ocean waves involves frequency dependent added mass and radiation damping as well as the linear and nonlinear mooring line characteristics. Usually, the added mass and radiation damping matrices can be estimated...

...Xiaorong Wu; Longbin Tao; Yuanlin Li Nonlinear roll damping has a profound influence on ship motions and stability in ocean waves. In this study, an experimental investigation is conducted on the nonlinear roll damping of a ship in regular and irregular waves. The random decrement method...

... systems marine systems structural engineering damping sensitivity analysis identification In Part 1 ( 1 ) of this two-part study, the nonlinear system identification methodology developed earlier by the authors for a single-degree-of-freedom (SDOF) system using the reverse-multi-input/single...