2,561 research outputs found

    Concept design of a fast sail assisted feeder container ship

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    An environmentally sustainable fast sail-assisted feeder-container ship concept, with a maximum speed of 25 knots, has been developed for the 2020 South East Asian and Caribbean container markets. The use of low-carbon and zero-sulphur fuel (liquefied natural gas) and improvements in operational efficiency (cargo handling and scheduling) mean predicted Green house gas emissions should fall by 42% and 40% in the two selected operational regions. The adoption of a Multi-wing sail system reduces power requirement by up to 6% at the lower ship speed of 15 knots. The predicted daily cost savings are respectively 27% and 33% in South East Asian and the Caribbean regions.Two hull forms with a cargo capacity of 1270TEU utilising different propulsion combinations were initially developed to meet operational requirements. Analysis & tank testing of different hydrodynamic phenomena has enabled identification of efficiency gains for each design. The final propulsion chosen is a contra-rotating podded drive arrangement. Wind tunnel testing improved Multi-wing sail performance by investigating wing spacing, wing stagger and sail-container interactions. The associated lift coefficient was increased by 32%. Whilst savings in sail-assisted power requirement are lower than initially predicted an unexpected identified benefit was motion damping.The fast feeder-container ship is a proposed as a viable future method of container transhipment

    Concept design of a fast sail assisted feeder container ship

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    A fast sail assisted feeder container ship concept has been developed for the 2020 container market in the South East Asian and Caribbean regions.The design presented has met the requirements of an initial economic study, with a cargo capacity of 1270 twenty-foot equivalent unit containers, meeting the predictions of container throughput derived from historical data. In determining suitable vessel dimensions, account has also been taken for port and berthing restrictions, and considering hydrodynamic performance. The vessel has been designed for a maximum speed of 25 knots, allowing it to meet the demand for trade whilst reducing the number of ships operating on the routes considered.The design development of the fast feeder concept has involved rigorous analyses in a number of areas to improve the robustness of the final design. Model testing has been key to the development of the concept, by increasing confidence in the final result. This is due to the fact that other analysis techniques are not always appropriate or accurate. Two hull forms have been developed to meet requirements whilst utilising different propulsor combinations. This has enabled evaluation of efficiency gains resulting from different hydrodynamic phenomena for each design. This includes an evaluation of the hydrodynamic performance when utilising the sail system. This has been done using a combination of model test results and data from regression analysis. The final propulsor chosen is a contra-rotating podded drive arrangement. Wind tunnel testing has been used to maximise the performance of a Multi-wing sail system by investigating the effects of wing spacing, stagger and sail-container interactions. This has led to an increase in lift coefficient of 32% from initial predictions. The savings in power requirement due to the sail system are lower than initially predicted. However, another benefit of their installation, motion damping, has been identified. Whilst this has not been fully investigated, additional fuel savings are possible as well as improved seakeeping performance.The design is shown to be environmentally sustainable when compared to existing vessels operating on the proposed routes. This is largely due to the use of low-carbon and zero-sulphur fuel (liquefied natural gas) and improvements in efficiency regarding operation. This especially relates to cargo handling and scheduling. Green house gas emissions have been predicted to fall by 42% and 40% in the two regions should the design be adopted. These savings are also due to the use of the Multi-wing sail system, which contributes to reductions in power requirement of up to 6% when the vessel operates at its lower speed of 15 knots. It is demonstrated that the fast feeder is also economically feasible, with predicted daily cost savings of 27% and 33% in the South East Asian and Caribbean regions respectively. Thus the fast feeder container ship concept is a viable solution for the future of container transhipment. <br/

    Parametric study of the influence of the wind assisted propulsion on ships

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    nologies to increase energy efficiency and reduce ship fuel consumption. Several measures have been identified, or even applied, with the potential to achieve substantial fuel consumption and emission reductions, like slow-steaming, bio-fuels, and alternative propulsion technologies. Slow steaming has been already analysed to a great extent, whereas biofuels have raised concerns about environmental impact and availability. Among alternative propulsion technologies, a resurgence in wind-assisted propulsion is observed in recent years, primarily due to its high potential for fuel consumption and emission reduction. Wind power is currently being developed through both conventional sails and modern alternatives. These include Flettner rotors, kites or spinnakers, soft sails, wing sails and wind turbines. In particular, Flettner rotors are rotating cylinders generating lift when immersed in a fluid stream. This paper presents a ship propulsion model study, able to account for the thrust force produced by the rotor accounting for different vessel speed and weather scenario. This paper aims to assess the improvement of the ship’s energy efficiency and optimise the ship operating conditions in terms of daily performance. The result clearly shows the potential reduction achieved in the propeller delivered power given using the rotor as an auxiliary propulsion device

    Regression Modelling Estimation of Marine Diesel Generator Fuel Consumption and Emissions

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    This study aims to estimate the fuel consumption of marine diesel generators onboard. Objective technical specifications and operational data on the ship\u27s power generating plants and port calls were collected from an oceangoing oil/chemical tanker and used to develop the mathematical model of the plant in the Python and MATLAB environment. The model consists of alternators, prime movers and load distributions of the ship’s power generating plant and provides information on fuel consumption in metric tons calculated based on hours of operation and specific fuel consumption data. Regression models have helped predict future fuel consumption for the plant and the optimal model for the dataset was identified by comparing four different algorithms. As the results have shown the Ordinary Least Squares Regression to be optimum, it was used to make one, five, and ten-year predictions. The predictions for one-year, five-year, and ten-year periods are 4,322,436, 10,684,860, and 18,615,472 t respectively. The selected model predicts fuel consumption with R2 of 0.999, MAE of 3.932, and RMSE of 2.935. Fuel consumption predictions facilitated plant emission calculation

    Study of The Technical Approach on Recent Fuel Efficiency to Reduce Ship Emissions

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    Engine emissions of ships have been highly concerned in the last decades. Most of the current ship operations worldwide are powered by the combustion engine. Advance ship powering is still on research and hard to implement directly. High cost in the application is the main issue. Meanwhile, the fuel engineering approach is proposed in the recent research to advance engine combustion, thus increasing the combustion efficiency and lowering the emissions target. This study aims to evaluate the development trend on the fuel efficiency technique to lower ship emissions. Emissions management, fuel conversion, and power conversion are the most research focus to improve fuel efficiency. However, implementing some of that research is still hard on ship operation. Technical and economic issues are the main reason. Moreover, fuel efficiency on ships is still highly based on management. Low cost, new combined fuel without separation, and less fuel treatment technology are proposed to avoid confusion on fuel consumption in the near future.

    Simulation model of a ship’s energy performance and transportation costs

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    Society faces a major challenge to reduce greenhouse gas emissions to limit the effects and propagation of climate change. As the main contributor to global trade, the shipping industry adds significantly to global greenhouse gas emissions and must actively work towards reducing, or eliminating, emissions in a short period.\ua0 This thesis contributes by developing a generic model for quick and accurate prediction of the fuel consumption of existing ships or newbuilds in operational conditions. The aim is to be able to predict the potential of fuel-saving measures, e.g., design features, retrofitting, alternative propulsion, and operational improvements, and evaluate the impact of such measures both, logistically and technically.A novel energy systems model called “ShipCLEAN” was developed, which provides the opportunity to predict the propulsion power, fuel consumption, and daily costs and income of ships in realistic operational conditions, i.e., a wide variety of drafts, speeds, and environmental conditions. ShipCLEAN is a unique coupling of a generic power prediction model and a marine transport economics model. Aside from a calm-water power prediction based on empirical and standard series methods, the power prediction model includes simulating alternative propulsion methods (i.e., wind-assisted propulsion), respects all environmental loads acting on a ship at sea (e.g., wind, waves, current), is valid for multiple operational conditions (i.e., speed and draft of the ship), and balances the forces and moments in four degrees of freedom. Validation studies using five example ships (a container ship, a tanker, a cruise ferry, and two RoRo ships) show good agreement of the predicted propulsion power with both model tests in the design condition and full-scale measurements in variable operational conditions. A detailed uncertainty analysis provides an overview of how to further increase the prediction accuracy. Special focus of the study is put on evaluating measures to decrease the emissions of ships through operational optimization, i.e., speed optimization, alternative propulsion concepts, and new design of zero-emission concepts. ShipCLEAN includes novel methods to evaluate the aerodynamic interaction effects of Flettner rotors on a ship (in between the rotors and between the rotors and the ship), to control the rpm of each rotor in an array on a ship and to evaluate the hydrodynamic forces acting on a ship sailing at a drift angle. Results from application studies show that fuel savings of around 3% are achievable by optimizing the speed profile of a ship in operation. Wind-assisted propulsion shows the potential to save up to 30% of fuel if applied to a tanker on a Pacific Ocean trade. It is concluded that flexible power prediction models requiring limited input data help to identify and quantify potential fuel savings and to identify motivators for ship owners and operators to apply fuel-saving measures. Further, it is concluded that four degrees of freedom analysis and methods to respect aero- and hydrodynamic interaction effects are crucial to accurately predict the performance of wind-assisted propulsion

    Techno-economic Analysis of Rotor Flettner in Container Ship 4000DWT

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    Rotor flettner is a kind of technology which developed and used in 21st century. This technology is very simple, cylindrical in shape, applied in the upper deck, and rotated by the electrical motor. This technology uses wind energy and applicating magnus effect to create propulsion force. Rotor flettner depends on the condition of the sea wind. The designer has to check the weather condition in its route before make a design of rotor flettner. This kind of technology is not only useful for the economic side, but also, for the environment. Rotor flettner can reduce the emission of a ship. It helps to gain some power to increase in fuel saving.The emission can be decreased by the increasing of fuel saving. So, this technology is a kind of environmentally friendly technology that can be used for the future innovatio

    Environmental inefficiencies of short sea shipping vessels by optimization processes based on resistance prediction methods

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    [Abstract]: Fulfilment of the progressive environmental normative involves a singular challenge for Short Sea Shipping (SSS), since it must maintain its competitiveness versus other transport alternatives. For this reason, over the last decade SSS vessels have been the subject of numerous analyses, in terms of operative research, and optimizations, from the marine engineering standpoint. Despite widespread awareness about the impact of a vessel’s resistance on environmental performance, many of the previous analyses were based on resistance prediction methods with low accuracy levels. This fact necessarily involves deviations regarding the expected sustainability of vessels. This paper attempts to quantify (in monetary terms) the environmental consequences due to this low level of accuracy. To meet this aim, it analyzes the environmental performance of an SSS feeder vessel, which was obtained from an optimization process based on standard resistance prediction techniques, when its propulsion power requirements for sailing at optimized speed were assessed through the Reynolds Averaged Navier–Stokes method in Computational Fluid Dynamic simulations. The findings show that standard resistance prediction methods without consideration of hull shape must be avoided, not only in the optimization process, but also for operative research, especially in free sailing analysis

    Environmental economic analysis of speed reduction measure onboard container ships

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    : The International Maritime Organization (IMO) has concerned significant care to the reduction of ship emissions and improvement of energy efficiency through operational measures. One of those measures is ship speed reduction, which is classified as a short-term measure; in which the speed is reduced below its designed value. The present paper aims at evaluating the potential energy efficiency, and environmental and economic benefits because of applying speed reduction measures. The research methodology depends on establishing a simple mathematical model for technical, environmental, and economical aspects because of this concept. As a case study, container ships from different categories in a range of 2500-15,000 twenty-foot equivalent units (TEU) are investigated. The results show that a 2500 TEU ship can comply with the energy efficiency existing ship index (EEXI) by reducing the service speed to 19 knots. While for the bigger ships, the service speed must be 21.5 knots or below. Furthermore, the operational carbon intensity indicator (CII) has been evaluated for the case studies and found that the CII rating will keep its score between A and C levels if the service speed is equal to or below 19.5 knots. Moreover, the annual profit margin of the ship will be calculated based on applying speed reduction measures. Based on the economical results, the annual profit margin value, and its corresponding optimum speed change with the size of the vessel and the applicable status of carbon taxes
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