Establishment of a validation and benchmark database for the assessment of ship operation in adverse conditions

The Energy Efficiency Design Index (EEDI), introduced by the IMO [1] is applicable for various types of new-built ships since January 2013. Despite the release of an interim guideline [2], concerns regarding the sufficiency of propulsion power and steering devices to maintain manoeuvrability of ships in adverse conditions were raised. This was the motivation for the EU research project SHOPERA (Energy Efficient Safe SHip OPERAtion, 2013-2016 [3-6]). The aim of the project is the development of suitable methods, tools and guidelines to effectively address these concerns and to enable safe and green shipping. Within the framework of SHOPERA, a comprehensive test program consisting of more than 1,300 different model tests for three ship hulls of different geometry and hydrodynamic characteristics has been conducted by four of the leading European maritime experimental research institutes: MARINTEK, CEHIPAR, Flanders Hydraulics Research and Technische Universität Berlin. The hull types encompass two public domain designs, namely the KVLCC2 tanker (KRISO VLCC, developed by KRISO) and the DTC container ship (Duisburg Test Case, developed by Universität Duisburg-Essen) as well as a RoPax ferry design, which is a proprietary hull design of a member of the SHOPERA consortium. The tests have been distributed among the four research institutes to benefit from the unique possibilities of each facility and to gain added value by establishing data sets for the same hull model and test type at different under keel clearances (ukc). This publication presents the scope of the SHOPERA model test program for the two public domain hull models – the KVLCC2 and the DTC. The main particulars and loading conditions for the two vessels as well as the experimental setup is provided to support the interpretation of the examples of experimental data that are discussed. The focus lies on added resistance at moderate speed and drift force tests in high and steep regular head, following and oblique waves. These climates have been selected to check the applicability of numerical models in adverse wave conditions and to cover possible non-linear effects. The obtained test results with the KVLCC2 model in deep water at CEHIPAR are discussed and compared against the results obtained in shallow water at Flanders Hydraulics Research. The DTC model has been tested at MARINTEK in deep water and at Technische Universität Berlin and Flanders Hydraulics Research in intermediate/shallow water in different set-ups. Added resistance and drift force measurements from these facilities are discussed and compared. Examples of experimental data is also presented for manoeuvring in waves. At MARINTEK, turning circle and zig-zag tests have been performed with the DTC in regular waves. Parameters of variation are the initial heading, the wave period and height

Berechnung des Gesamtwiderstandes eines Schiffes

A Navier-Stokes solver has been further developed for the computation of turbulent free surface ship flows. The method allows for the analysis of the complete flow, including the waves generated by the ship, flow separation, wake distribution and the total ship resistance. The dynamic sinkage and trim are not yet taken into account. The free surface is captured with a Level Set technique and the turbulence is modelled with the k-#omega# model. Computations were performed in model scale for the Series 60 ship and for a tanker. The results are mostly in very good agreement with experimental data. The grids used, containing roughly 400 000 cells, are still too coarse for quantitative accurate resistance predictions. Due to the long computational time of several days on a normal workstation, the method is not yet sufficiently developed for practical applications. (orig.)SIGLEAvailable from TIB Hannover: RN 3150(1632) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Ein Finite-Volumen-Verfahren zur Berechnung turbulenter Schiffsumstroemungen

A method for calculating turbulent flows around ships is described and its capabilities are investigated by comparison with experimental data. The Reynolds averaged Navier-Stokes equations and the continuity equation in Cartesian velocity components are discretized on a boundary adapted grid in accordance with a finite volume method. A structured 3-d grid for the overall arithmetic area is generated numerically. An algebraic turbulence model is applied, while the use of wall functions is dispensed with. The convection terms are approximated by a second order upstream difference scheme (LUDS) and the diffusion terms are approximated by central differences (CDS). A special interpolation technique of mass flows in accordance with Rhie and Chow is used in order to prevent numerically induced pressure oscillations due to the selected non-offset arrangement of flow variables in the grid. The resulting nonlinear algebraic system of equations is iteratively solved in accordance with the SIMPLE method. (orig./AKF)Available from TIB Hannover: RA 489(540) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

ROLL-S: Numerische und experimentelle Untersuchungen grosser Rollbewegungen. Teilvorhaben: Erzeugung von Seegangsspektren fuer Finite-Volumen-Methoden und Anwendung auf realistische Schiffsformen

SIGLEAvailable from TIB Hannover: RN 3150(1648) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Numerische Widerstandsprognose

A Navier-Stokes solver has been further developed to compute turbulent free surface model and ship flows. The method allows for the analysis of the complete flow i.e. the generated waves, flow separation, wake distribution, ship resistance and the dynamic sinkage and trim. The implemented method solves the RANS equations in a block structured colocated numerical grid with use of the SIMPLE algorithm and the program has been parallelised to reduce the computational time. The free surface is computed with a Level-Set method and the turbulence is modeled with the k-#omega# model using wall functions. Computations are carried out for different types of ship models and one full scale ship. Most of the results agree well with experimental data, but the used grids are still too course for accurate resistance predictions. For practical application to ship model flow the numerical method is sufficient robust and the grid generation time is reduced to an acceptable level when using a commercial grid generator. Nevertheless the computation of the full scale flow is sensitive to numerical details. (orig.)SIGLEAvailable from TIB Hannover: RN 3150(1642) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Manoevriermodellversuche zur Validierung theoretischer Ansaetze im Verbundvorhaben ROLL-S Schiffs- und Ladungssicherheit bei grossen Rollwinkeln im Seegang Schlussbericht

SIGLEAvailable from TIB Hannover: RN 3150(1650) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Manoevriermodellversuche zur Validierung theoretischer Ansaetze im Verbundvorhaben ROLL-S Schiffs- und Ladungssicherheit bei grossen Rollwinkeln im Seegang Schlussbericht

SIGLEAvailable from TIB Hannover: RN 3150(1650) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Numerische Verfahren zur Antriebsleistungsprognose

Available from TIB Hannover: RN 3150(1587)+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman