In this paper, the need to develop an advanced and efficient propulsion system, to support missions demanding increased endurance of Unmanned Underwater Vehicles is investigated, and a conceptual model is proposed by ...
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ISBN:
(纸本)9781728146768
In this paper, the need to develop an advanced and efficient propulsion system, to support missions demanding increased endurance of Unmanned Underwater Vehicles is investigated, and a conceptual model is proposed by varying several operational and design parameters. Electric propulsion system (EPS), in which battery is the power source, electric motor is the fundamental driving element and propellers are the core driven equipment, is a very important concept for an energy efficient propulsion of underwater vehicles. The basic mathematical design of proposed EPS accumulates the vital abilities to be less noisy and more energy efficient, provide high initial torque along with high speed and enough endurance to acquire the desired target range. The simulations using MATLAB have been carried out to produce graphs between drag and multiple operational and design variables. The out-turns of this paper are typically based upon the simulations and analytical aftermaths. The suggested model of propulsion system bestows a clear understanding that the basal operationalparameters such as speed and depth of the underwater vehicles are related directly with the drag whereas the fundamental design specifications such as shape, surface area and weight of the submersible vehicles also possess, physically, a direct relation with the drag force.
With increasingly strict emission regulations, engine manufacturers are developing new strategies and technologies to reduce exhaust gas emissions. Thus, exhaust gas emission limits and test procedures for internal co...
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With increasingly strict emission regulations, engine manufacturers are developing new strategies and technologies to reduce exhaust gas emissions. Thus, exhaust gas emission limits and test procedures for internal combustion engines, as well as for other combustion systems, have had a market impact upon the development of the engines and systems. Because of the requirement for good fuel economy and low NOx emissions that dominate engine design practice, reducing NOx emissions requires a detailed understanding of the chemical pathways for emission formation. Over the past several years, an increasing number of models for the formation of exhaust gas emissions have been implemented. In recent years, both environmental and economic concerns have stimulated a strong interest in using natural gas for internal combustion engines. One of the reasons to use natural gas as the fuel in engines is the ability to produce relatively little NOx. This paper deals with the effects of design and operationalparameters on the NOx emissions of a turbocharged natural gas engine. Within the framework of a detailed research and development project in cooperation with university and industry, a gas engine series used in combined power plants has been optimised regarding power, efficiency and emissions. Since an evaluation of the emission behaviour is increasingly important, the nitrogen oxide emission and its dependence on engine operational and geometrical conditions were investigated by using a zero dimensional reaction kinetic model as well as experimental studies. (C) 2002 Elsevier Science Ltd. All rights reserved.
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