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Item type:Publication, Access status: without files , Improvements in the prediction of the wave making resistance from potential flow by using transverse wave cut methodsThe reliable and correct determination of the wave resistance is the key to an efficient ship design, as the wave resistance is one on the major factors concerning building and operational costs. In this paper the authors present a new approach to transverse wave cut analysis to overcome the major shortcoming of the resistance prediction from potential flow: a numerically stable and physically sound estimate for the magnitude of the wave making resistance.Publicationtype: Conference Paper33 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Design aspects of a high speed monohull RoPax ferry(American Society of Mechanical Engineers (ASME), 2015-05); ; ; ; This paper describes the design process of a high speed mono hull RoPax ferry which operates at a Froude number of 0.4. The design task was quite challenging, as two possible transport concepts were in principle possible: Two ships were needed with a total speed of 50knots, which could result in a combination of a 30kn high speed Catamaran plus a conventional 20kn RoPax Ferry or alternatively in two identical sister vessels of 25kn each. The solution with the high speed catamaran plus the conventional RoPax-Ferry defined the total cost budget, which must not be exceeded by the design of the two sister vessels. This resulted in a tough boundary condition and made life cycle cost evaluations necessary. Due to harbor restrictions, the length of the ships was limited by abt. 110m, resulting in a Froude number of abt. 0.4. This resulted in high costs for the propulsion system. The ferries should initially have open RoRo-Cargo spaces for cost reasons, which made the stability requirements (weather criterion plus Stockholm Agreement) quite challenging. This also strongly influenced the design of the final hull form. As the ship is very sensitive to weight, detailed steel structure optimizations had to be carried out to optimize the main grillage systems of the vehicle decks. The hull form and the appendage design required careful optimization to guarantee the required service speed with the engine power which was available in the price budget. As no vessel of comparison was available, the speed power estimation as well as all design tasks had fully to rely on numerical predictions. As the ship had further demanding requirements for course keeping and comfort in waves, the optimization of the hull form must include also these issues. The paper shows that the design of complex ships is actually a holistic task which includes many engineering disciplines. The paper also shows that 1st principle based design methods can support the design process of specialized vessels significantly.Publicationtype: Conference Paper121 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Optimized propulsor retrofit for slow steaming for a post pan-max container vesselShips are typically designed for a life cycle of about 20-25 years, with a specific transportation task, that suits the instant or estimated requirements of the owner or operator. Anyhow the business model might change due to a multitude of reasons and force the owner to buy new ships or modify the existing. Such an event took place in the year 2008 with the beginning of the financial crisis and the resulting recession, which lead to a drastic decrease of the global volume of cargo. This paper describes the re-design of the propulsion system of an existing post panmax container vessel to suit the new economical boundary conditions.Publicationtype: Conference Paper54