MOPS

Methodenbanksystem für Offshore- und Polar-Systeme

gefördert durch

BMWi - Bundesministeriums für Wirtschaft und Energie

Partner

Pella Sietas, OVERDICK, MAREVAL, FSG, TUHH

Laufzeit

01.04.2016 - 31.03.2019

Im Rahmen des Vorhabens wird eine Methodensammlung zur Berechnung von Problemen aus der Offshore-Industrie innerhalb einer schiffbaulichen Entwurfsumgebung entwickelt. Es gibt methodisch große Gemeinsamkeiten zwischen Schiffbau und der Offshore-Industrie, obwohl die zu berechnenden Strukturen sehr unterschiedlich sind. Durch die Energiewende tritt nun verstärkt das Problem auf, Offshore- Probleme mit konventionellen Schiffen angehen zu wollen. Dadurch werden verstärkt Berechnungen nachgefragt, die an der Schnittstelle zwischen schiffbaulichen Problemen und solchen aus der Offshore-Industrie liegen. Dieser Entwicklung trägt das Vorhaben Rechnung: Eine bewährte schiffbauliche Entwurfsumgebung soll gezielt für Problemstellungen aus der Offshore-Industrie erweitert werden. Dazu gehören nicht nur neue Beschreibungsgrundlagen und Datenmodelle für Offshore-Strukturen, sondern auch erweiterte Berechnungsverfahren und das zugehörige Postprocessing.

Mehr Informationen erhalten Sie bei den Ansprechpartnern: Charlott Weltzien, Michał Josten

Publikationen

Folgende Publikationen wurden im Rahmen dieses Forschungsvorhabens erstellt:

[146882]
Title: Calculation of the Seakeeping Behaviour of a Jack-Up Vessel During the Jacking Sequence in Time Domain
Written by: Maximilian Liebert
in: ISOPE, Shanghai, China 2020
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[pdf] [BibTex]

Note: MOPS

Abstract: Offshore wind farms play a decisive role in the exit from fossil-fuel energy in Germany. These offshore wind turbines are oftentimes installed with jack-up vessels. At the site of operation these vessels lift their hull above the water surface by extending their jacking legs. The vessel´s seaway-induced motions at the moment of initial contact between leg and seabed define the critical dynamic structural loads onto the legs and the jacking mechanism, which have to be minimised. Therefore, an analysis of the seakeeping behaviour during the sensitive jacking sequence is required in the early design stage in order to define the vessel´s operational limits of sea state. The ship design environment E4 is an open software framework, being developed by the Institute of Ship Design and Ship Safety, which provides various methods for the dynamic analysis of a digital twin of the actual ship. However, these methods are restricted to conventional ship-type structures whereas the analysis of the seakeeping behaviour during the jack-up process further requires a consideration of the jacking legs´ hydrodynamic influence. For a holistic analysis of the seakeeping behaviour, the forces onto the legs were thus accounted for by a Morison approach in the calculation of the required response amplitude operators. This paper presents the calculation of the vessel´s seakeeping behaviour in irregular waves in time domain on the basis of these modified RAOs. The applied method calculates the vessel´s response motions in six degrees of freedom. Since the roll motion tends to show the largest response amplitudes in a seaway this degree of freedom is calculated in a non-linear way with respect to the wave amplitude and the roll angle by solving its equation of motion. The motions in the residual degrees of freedom are calculated from the underlying linear response amplitude operators. The achieved results are validated by model tests of a jack-up vessel with extended legs in irregular long-crested waves. This extended method represents a quick computational tool for early design applications in order to determine limiting sea states for the jacking sequence, which is a major design aspect of such ships.