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Added mass --- Hydrodynamic forces --- Fenders --- Ship anchors

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Le transport fluvial est l'un des types de transport les plus sûrs, c'est pourquoi il est souvent utilisé pour le transport de matières dangereuses. Le transport de matières dangereuses par voie fluviale est régi en Europe par un accord appelé l'ADN. Selon cet accord, la capacité maximale d'un réservoir d'un navire citerne ne peut dépasser les 380 $ext{m}^3$, à moins qu'un calcul ne prouve que le dépassement de la capacité limite ne constitue pas un risque.

Ce calcul est réalisé en suivant une procédure en 13 étapes décrites dans l'ADN. La première étape de ce calcul est la création d'une construction de référence satisfaisant les prescriptions de l'ADN. Ce navire de référence a d'abord été dimensionné et son échantillonnage a été réalisé en suivant les réglementations d'une société de classification, le Bureau Véritas. Lorsque cette procédure est appliquée, l'étude est réalisée pour un navire avec des citernes dont la capité maximale dépasse la limite autorisée. Cependant, la procédure a été appliquée dans ce travail en créant un navire alternatif à partir du navire de référence. La différence entre les deux navires est une partie de la structure se trouvant dans les doubles bords du navire, où les porques ont été remplacées par une structure innovante.

La procédure nécessite l'étude par éléments finis de la collision entre les deux navires avec des autres bateaux. Cette étude a été réalisée sur le logiciel LS-DYNA. Différents scénarios de collision ont été modélisés et étudiés afin de connaître l'énergie absorbée pendant la collision avant la rupture de la citerne pour les deux types de navires.

La fin de la procédure de l'ADN est l'évaluation de la probabilité de rupture de la citerne. Cette probabilité est calculée à partir des énergies de collision déterminées à différents scénarios grâce à l'étude par éléments finis. Cette procédure nous permet de pouvoir comparer objectivement l'efficacité d'une structure d'un bateau lors d'un impact, et de valider l'utilité de la structure innovante qui a été créée lors de cette étude.

Finite element study --- ADN --- Ship-Ship collision --- Ingénierie, informatique & technologie > Ingénierie aérospatiale

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Shipyards around the world are trying to create and strengthen competitive production advantages that guarantee their sustainable development in the regional and global market. The shipbuilding business continues demanding the design and implementation of new strategies to improve and maximize the ship production processes, allowing to reduce the cycle construction time for new ships and optimize the resources associated with each project. 

This research proposes to demonstrate and explain the general aspects that should be considered for the implementation of "advanced outfitting" concept as a strategy in shipbuilding processes. At present, many small and mid-tier shipyards only install pipes on-block level in its new construction projects, leaving the installation process of the largest percentage of equipment after the ship’s hull has been manufactured and assembled. The "advanced outfitting" process is a strategy currently used by the most modern shipyards in the world and allows the installation of the largest amount of equipment (machinery, pipelines, auxiliary machinery, etc.) in the earliest stages of construction, especially during the assembly of each block that compose the hull. The result of this investigation will become as a guide for any mid-tier shipyard to understand and implement the general concept of advanced outfitting techniques, and how to assess its impact on future shipbuilding projects. However, small shipyards could use this guide to understand this concept as well. 

The document is focused on industrial purposes, not only to show the aspects should be checked to assess the level of outfitting processes in shipbuilding projects compared with global shipbuilding behavior and how to improve it, but to influence strategically to the mid-tier shipyard companies, proposing alternatives for achievement the future shipbuilding projects and support some decisions in terms of outfitting. Different sources of data and information were used, including fieldwork through observation, study of shipbuilding projects and interviews during internship time in CRIST shipyard (Gdynia, Poland), as a part of EMSHIP program, but also study of many documents related to ship production and outfitting technics. 

The study shows and explains all the main necessary aspects to implement the advanced outfitting concept, from optimization of layout, until design and engineering aspects, production aspects, and project management. Also, some logistics aspects are studied to complement the different levels involved in shipbuilding strategy. Finally, a cost-benefit analysis was established to demonstrate the positive influence of advanced outfitting on shipbuilding projects and validate the hypothesis that this methodology could improve the productivity in mid-tier shipyards, reducing the cost and time for each project, and how it could impact the future shipbuilding projects.

Advanced outfitting, outfitting process, ship production, shipbuilding --- Ingénierie, informatique & technologie > Ingénierie civile

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The master thesis was focused on the numerical prediction of the static hydrodynamic derivatives, required to solve the ship manoeuvring problem. The hydrodynamic forces and moments acting on the considered ship (KVLCC2) with the influences of the drift and rudder deflection angles were computed using CFD techniques, in correlation with the standard PMM (Planar Motion Mechanism) static tests. The corresponding hydrodynamic derivatives were calculated and the characteristics of the turning circle and Zig-Zag manoeuvres were estimated on the basis of the simulated ship trajectory. The master thesis is composed by three main parts: - The estimation of the preliminary hydrodynamics performance (ship resistance, powering and manoeuvring) using the PHP software platform, developed at the “Dunarea de Jos” University of Galati; - The computation of the hydrodynamics forces and moments acting on the 1/58 KVLCC2 ship model, during the static drift, static rudder and static drift and rudder motions, using CFD instruments (SHIPFLOW code); - The simulation of the ship trajectory and the estimation of the turning circle characteristics using the hydrodynamics derivatives obtained on the basis of CFD computation and statistical relations (Clarke, Gedling and Hine). In the first part, specific methods dedicated to the initial design stage were used: Holtrop-Mennen for ship resistance prediction and propeller series B-Wageningen in order to estimate the hydrodynamic characteristics in open water. From manoeuvrability view point, the Voitkounsky model was used to compute the hydrodynamics of the rudder (including the optimum position of the rudder stock), and the Brix model was dedicated to check the rudder cavitation. Also, Abkowitz model and statistical relations proposed by Lyster and Knights were introduced to estimate the turning circle characteristics. The second part was dedicated to estimate the hydrodynamics forces and moments acting on the ship with the propeller and rudder deflection influences, using the viscous flow theory (RANS), in deep water condition, for 0.142 Froude number, corresponding to the design speed. The potential flow theory was applied for wave resistance computation of the bare hull, and the experimental model tests performed by MOERI were used in order to validate this procedure, for a range of Froude numbers between 0.101 and 0.147. The static drift, static rudder and combined static drift and rudder numerical simulations in viscous flow assumption were done, in the following conditions: - The static drift angle, β, was varied with 2° step, in the range of -20° to 20°, the rudder being kept in the Center Line; - The static rudder deflection angle, δ, was varied with 10° step, in the range of -40° to 40°, the hull being kept on the straight ahead course; - Also, all the static drift and rudder deflection combinations were considered. The obtained hydrodynamics lateral forces Y were compared with the experimental results provided by MOERI, for static drift and static rudder. In the last part, the numerical prediction of the static hydrodynamic derivatives and the simulation of the turning circle and Zig-Zag manoeuvres were performed on the basis of two specific codes (POLINEW and PMMPROG) developed at the “Dunarea de Jos” University of Galati. The characteristics of the turning circle and Zig-Zag manoeuvres were determined, the IMO criteria being used to establish the manoeuvring performance of the ship. 
In conclusion, the CFD techniques may be introduced in the design process in order to increase the quality of the hydrodynamic performance prognosis, including the manoeuvrability characteristics.

ship manoeuvring --- static hydrodynamic derivatives --- CFD Techniques --- KVLCC2 model. --- Ingénierie, informatique & technologie > Ingénierie civile

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The irregular demand in ship types, besides, limited timeframe to deliver either navy or commercial ships play a great role in shipbuilding industry. Therefore, shipyards are trying to reduce delivery times also reducing production cost. The main goal of this master thesis is to develop proposals for restructuring workflow of mid-tier shipyard using methodology that [WAN 10-2] proposed, rough layout concept and discrete-event-simulation (DES). 

In order to accomplish with this goal, brief explanation about ship production process is given, description of simulation used in this field. Besides, brief analysis of capacities in diverse software and capacities of the shipyard used as case of studies. 

As introduction of this type of study, using as case of study a navy ship called Offshore Patrol Vessel – OPV80. The first existing condition was modeled and validated considering averages values for workstations. In order to get better understanding of production rate, assessing effect of each workstation on overall production process is done. 

Following, using this existing and validated model was possible creation of various scenarios. Two scenarios were performed in endeavor to improve productions time. One of this scenarios deal with the inclusion of automation in production line and the other deal with layout of the workflow proposed to reduce the time used to move the material along the production line. 

In this master thesis simulation analysis had shown how to evaluate either risk or impact of future investments or changes in production line, varying parameters and measure outputs. Furthermore, considering the influence of each parameter in the production line and bottleneck assessment.

Ship Production, Simulation, Mid-tier Shipyard, and Production Line --- Ingénierie, informatique & technologie > Ingénierie civile