Maritime Research Institute Netherlands

About: Maritime Research Institute Netherlands is a nonprofit organization based out in Wageningen, Netherlands. It is known for research contribution in the topics: Turbulence & Computational fluid dynamics. The organization has 200 authors who have published 279 publications receiving 4382 citations. The organization is also known as: MARIN.

Ocean Energy Systems Wave Energy Modelling Task: Modelling, Verification and Validation of Wave Energy Converters

Abstract: The International Energy Agency Technology Collaboration Programme for Ocean Energy Systems (OES) initiated the OES Wave Energy Conversion Modelling Task, which focused on the verification and validation of numerical models for simulating wave energy converters (WECs). The long-term goal is to assess the accuracy of and establish confidence in the use of numerical models used in design as well as power performance assessment of WECs. To establish this confidence, the authors used different existing computational modelling tools to simulate given tasks to identify uncertainties related to simulation methodologies: (i) linear potential flow methods; (ii) weakly nonlinear Froude–Krylov methods; and (iii) fully nonlinear methods (fully nonlinear potential flow and Navier–Stokes models). This article summarizes the code-to-code task and code-to-experiment task that have been performed so far in this project, with a focus on investigating the impact of different levels of nonlinearities in the numerical models. Two different WECs were studied and simulated. The first was a heaving semi-submerged sphere, where free-decay tests and both regular and irregular wave cases were investigated in a code-to-code comparison. The second case was a heaving float corresponding to a physical model tested in a wave tank. We considered radiation, diffraction, and regular wave cases and compared quantities, such as the WEC motion, power output and hydrodynamic loading.

Coupled Mooring Analysis for a Deep Water CALM Buoy

Abstract: The effect of the mooring loads on floater motions can be significant for small water plane area floaters like CALM buoys. Not only does the mooring system contribute to the static restoring force components, but the dynamic behaviour of the mooring lines also affects the inertia and damping of the moored CALM buoy. The results from model tests with a moored CALM buoy were compared with the results from two series of time-domain computer simulations. First, fully dynamic coupled simulations were carried out, in which the interaction between the floater motions and the dynamic mooring line loads was modelled for all 6 modes of motion. Second, quasi-static simulations were carried out, in which only the (non-linear) static restoring force characteristics of the mooring system were taken into account. The comparison of results from the simulations and the model tests clearly indicates that the fully dynamic coupled simulations show a much better correspondence with the model test results than the quasi-static simulations. It is concluded that for the simulation of the behaviour of a moored CALM buoy in waves a fully dynamic coupled mooring analysis is essential.

Investigation of a semi-submersible floating wind turbine in surge decay using CFD

Abstract: The hydrodynamic damping estimation of the surge motion and the flow characteristics of a moored semi-submersible floating offshore wind turbine is the focus of this paper. The numerical su...

State-of-Art on Vortex-Induced Motion: A Comprehensive Survey After More Than One Decade of Experimental Investigation

Abstract: After one decade of experimental investigation, the Vortex-Induced Motion – VIM phenomenon deserves a comprehensive survey concerning the advances related to its understanding, mainly under the consideration of the fundamental aspects that keep it in a close relationship to the dynamic behavior of the same phenomenon acting on slender bodies, the well known Vortex-Induced Vibration – VIV. A considerable amount of results can be found in the literature, although there are few works dealing with a general view of the problem. Probably, the main reason for such a large amount of works with no interaction between themselves and, consequently, without a common understanding about VIM might be due to its technological origin, featured by huge platforms with a variety of geometrical details, which ends up placing the researches more on the field of the faithful reproduction of the features in small-scale and less on the global understanding of the phenomenology regardless the floating system, e.g. a spar platform, a monocolumn or even a semi-submersible or a tension-leg platform. Obviously, no one should disagree that there is part of the research that must keep a faithful relationship with the full scale, however, in most of them it is possible to identify the common fundamentals concerning the fluid-structural interaction. The aim of the present work is to address a comprehensive evaluation of the experimental investigations during the past decade on the VIM, trying to gather a general understanding about its phenomenology including some comparisons to VIV. As a result, some relevant aspects are pointed out for a more prospective way of research.Copyright © 2012 by ASME