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MAROFF-2-Maritim virksomhet og offsh-2

Sea Trials and Model Tests for Validation of Shiphandling Simulation Models

Awarded: NOK 13.6 mill.

The main objective of the project has been to develop and apply a method for validation of numerical ship models. Numerical models in engineering tools can be used for different purposes such as studies of ship manoeuvring characteristics in deep, open waters, design of fairways, ports and quays. Simulation models become an integrated part of modern design tools making it possible to include manoeuvring performance as a design parameter. Furthermore, numerical ship models are used in training simulators for deck officers and pilots. Verification and validation of simulation models are closely intertwined with access to benchmark data and the accuracy of such data from model tests and sea trials. This project has access to sea trials from a number of ships. The Norwegian partners have performed model tests and sea trials with five ships (NTNU's research vessel, "Gunnerus", the gas driven ferry, "Landegode", and three offshore vessels, the Island Offshore, "Island Condor", and the Havyard "Polarsyssel" and "Vestland Mira".). The foreign partners have used other case vessels (a triple E-class container vessel (Flanders Hydraulics/Ghent University), a small container vessel (Singapore Maritime Academy) and university research vessels belonging to University of Sao Paulo and Tokyo University of Marine Science and Technology). For the Norwegian case vessels, MARINTEK has performed different types of model tests. The focus has been on tests with the Hexapod system as a Planar Motion Mechanism ? PMM. A new method for analysing model test data has been developed to generate input data to MARINTEK's ship simulation tool VeSIM. The project has shown the importance of selecting model test parameters (for surge, sway and yaw) representative of critical manoeuvre for the actual vessel. When the parameters are well selected, it is shown that numerical predictions compare well with sea trial results. The project has funded two scholarships at the NTNU: one PhD and one post-doc. The candidates have studied uncertainty in sea trial data and the possibility of obtaining a vessel's manoeuvring performance from service data. Their works have been based on data from "Gunnerus" and "Landegode". The project started in April 2013 and ended in December 2016. The project budget was approximately 18 million NOK. Project results will be presented at a dedicated validation session at the OMAE 2017 Conference in Trondheim (June 2017). The Norwegian partners were MARINTEK, the NTNU, Rolls-Royce Marine, Island Offshore, Torghatten Nord, SMSC (2013-2014), Marine Cybernetics (2014-2016) and Havyard Design & Solutions (2015-2016). The foreign partners were Flanders Hydraulic Research, Ghent University, Tokyo University of Marine Science and Technology, Singapore Maritime Academy, University of São Paulo and Instituto SINTEF do Brazil (2013-2014)."

Validation of simulation models for ships should be given high priority as such models are increasingly being used for both engineering studies (documenting manoeuvring characteristics, investigating operational limits in restricted waters, port design an d investigation of accidents) and training purposes (sea time reduction, familiarization, advanced and critical operations). In general, simulation models for ships are more generic than those applied for other transport means such as aircraft, trucks, or cars. Norwegian shipowners invest in high value specialized vessels with efficient control systems. More ship specific simulation models are needed for such vessels to optimize operational procedures and enhance operational performance of navigation off icers. All research partners in the project have developed and are using numerical simulation models to study ship manoeuvring characteristics in open sea and in restricted waters, such as waterways and ports. However validation of these simulation models has, until now, been done in a mostly superficial way. The main research task in this project is to perform benchmark studies comparing model outcomes to results from specific or in-service field tests of selected ships. In previous validation studies su ch as for Esso Osaka and the vessels studied in the SIMMAN 2008 context, IMO's standard manoeuvres have been used for comparison of simulation outcomes and test results. From shipmasters and pilots, as well as scientists, it has been commented that the IM O Standard manoeuvres are not representative for ship operation at low speed and in confined waters. Experienced ship masters from participating shipping companies will take part in project workshops to specify new low speed and shallow water tests that s hould be used in the validation study for low speed shiphandling.

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MAROFF-2-Maritim virksomhet og offsh-2