... ABSTRACT Free decay tests are less onerous to carry out compared to experiments that include waves. These tests can also shed light on hydrodynamic characteristics of a device, such as added mass, stiffness and damping. This knowledge can then inform numerical models set up for the device...

..., free decay test, platform dynamic response and mooring line tension and the comparisons show good consistency. The test cases considered in this study are those proposed in the 1st FOWT Comparative Study. INTRODUCTION As an important composition of renewable energy, wind energy has been the subject...

...ABSTRACT ABSTRACT The performance of the overset meshing tool implemented in the opensource Computational Fluid Dynamics (CFD) software OpenFOAM© is investigated in this work. The method is validated against experimental results of free decay tests of a freely-floating vertical cylinder...

... white-noise wave test arctic engineering mooring system model test smod coefficient simulation vlf seabed condition motion response calculation free decay test engineering water depth single module heave sway natural period subsea system wave test constant water depth type...

... motion excitation device marine transportation logarithmic decrement liquified natural gas roll motion model test coefficient equivalent roll free decay test roll angle subsea system numerical simulation artificial intelligence midstream oil & gas Study on the Estimation Methods...

.... engineering free decay comparison vessel motion rao offshore pipeline free decay test hydrodynamic coefficient coefficient model test hydrodynamic analysis top tension upstream oil & gas numerical simulation operation model test result motion rao numerical model midstream oil & gas j...

... the free decay tests and some coupled wind and waves tests. The simulations are finally compared to the results obtained in the experimental campaign at MARINTEK. INTRODUCTION During the last years, the offshore wind energy has become one of the most promising renewable source of energy. However...

... application tlp in-place condition model test fpso platform floating production system natural period frequency probe subsea system wave elevation free decay test model test numerical simulation tension tendon tendon tension tlp water depth prediction tendon upstream oil...

... Abstract The performance of the active heave compensator(AHC) during the subsea installation is investigated by means of experiments and numerical simulation. The added masses of the subsea structures are estimated by conducting the free decay tests. The performance of AHC is investigated...

... Abstract In the present paper, effect of heave plate on heave response of spar is investigated for spar with single and two heave plates. Free decay test is conducted experimentally on 1:50 scale model of spar without heave plate and spar with single heave plate for finding the heave natural...

... and mf is the displaced fluid mass. Here the mass ratio of the whole system is 146. The damping ratio can be obtained from a free decay test provided and released by a initial external force on the structure 1 0 1j 2 )(lnM j jNN M YY (1) where YN+j is the vibration amplitude of the (N+j)th...

... coefficient of floating offshore wind turbine (FOWT) was obtained from the free decay test. Different wave directions, wave environments, drafts, wind intensities, current speeds and combined wind/wave/current were applied to study the instability of FOWT and operating conditions. The six-degree-of freedom...

.../RIFLEX/AeroDyn (SRA) code based on the WAMIT results. Free decay tests comparisons show very good agreements of natural frequencies in different modes but higher damping ratios are predicted by CFD model which might be due to the simplification of drag forces in SRAcode Comparison of TLPWT responses...

... or accelerate vertically about its center of gravity and the prescribed motions are defined through: G a h h ( t ) a sin( 2pit / T ) y ( t ) a sin( 2pit / T ) = = (6) where ai, Ti stand for the amplitude and the period of the corresponding motion. When the free-decay tests are examined, the body is assumed...

... Plutonio (Angola, 1310m), and Kizomba A & B (Angola, 1200m, 1000m). natural period moored buoy moored case stiffness model test free decay test upstream oil & gas mooring system heave surge buoy deepwater oil subsea system calculation viscous modeling rao coefficient...

.... & & bWGMaWGM BBv nn s 2 21 4 32 += += (7) Coefficients a and b are obtained from the results of free decay tests of the model. n is a natural angular frequency of the ship. The exciting roll moment Q is calculated by Froude-Krylov force in accordance with the researches of Tasai et al. (1981) when...

... the conventional added mass and wave-radiating damping, they are quadratic forces in wave amplitude. The wave drift added mass is measured in the present work from a free decay test or a forced slow oscillation test. The model is either a circular cylinder or an array of four circular cylinders. Experimental...

... and storage platform (Halkyard, 1996). heave heave response upstream oil & gas natural period keel joint free decay test keel plate interaction buoyancy friction heave motion spar hull interaction subsea system spar platform model test contribution spar riser Proceedings...

... data quality wavelet ridge technique time series amplitude nonlinear spring continuous wavelet transform instantaneous frequency wavelet transform free decay test frequency surge response oscillation equation natural frequency natural period nonlinearity spar platform...

... that gravity stability oscillation ship free decay roll motion deck compartment compartment experiment roll motion free decay test coefficient extinction curve natural roll period modeling & simulation marine transportation equation water surface roll extinction curve Proceedings...