A novel nuclear-powered propulsion system for ship

International Nuclear Information System (INIS)

Liu Tao; Han Weishi

2003-01-01

A novel nuclear-powered propulsion system for ship is presented in this paper. In this system, a minitype liquid sodium-cooled reactor is used as power; alkali-metal thermal-to-electric conversion (AMTEC) cells are utilized to transform the heat energy to electric energy and superconducting magneto-hydrodynamic (MHD) work as propulsion. This nuclear-powered propulsion system has great advantages in low noise, high speed, long survivability and simple manipulation. It has great significance for the development of propulsion system. (author)

Fault Monitoring and Re-Configurable Control for a Ship Propulsion Plant

DEFF Research Database (Denmark)

Blanke, M.; Izadi-Zamanabadi, Roozbeh; Lootsma, T.F.

1998-01-01

Minor faults in ship propulsion and their associated automation systems can cause dramatic reduction on ships' ability to propel and manoeuvre, and effective means are needed to prevent that simple faults develop into severe failure. The paper analyses the control system for a propulsion plant on...

A Study on the Propulsion Performance in the Actual Sea by means of Full-scale Experiments

Directory of Open Access Journals (Sweden)

Jun Kayano

2013-12-01

Full Text Available The IMO has adopted Energy Efficiency Design Index (EEDI, Ship Energy Efficiency Management Plan (SEEMP and Energy Efficiency Operational Indicator (EEOI in order to reduce GHG emissions from international shipping. And, the shipping industry is required to develop and improve the energy saving ship operation technologies to meet the above IMO guideline. The weather routing is one of the energy saving navigation technologies and widely adopted by oceangoing merchant ships. The effectiveness of the weather routing mainly depends on the accuracy of weather forecast data and the ship’s propulsion performance prediction. The propulsion performance in the actual sea is usually predicted using the Self Propulsion Factors obtained by model tests. It is necessary to understand the propulsion performance characteristics in the actual sea conditions for the improvement of propulsion performance prediction. From the above points of view, the authors performed full-scale experiments using a training ship in order to investigate the propulsion performance characteristics in the actual sea. This paper describes the analysis results on the characteristics of Power Curves and Self Propulsion Factors under various weather and sea conditions.

The influence of the waterjet propulsion system on the ships' energy consumption and emissions inventories.

Science.gov (United States)

Durán-Grados, Vanesa; Mejías, Javier; Musina, Liliya; Moreno-Gutiérrez, Juan

2018-08-01

In this study we consider the problems associated with calculating ships' energy and emission inventories. Various related uncertainties are described in many similar studies published in the last decade, and applying to Europe, the USA and Canada. However, none of them have taken into account the performance of ships' propulsion systems. On the one hand, when a ship uses its propellers, there is no unanimous agreement on the equations used to calculate the main engines load factor and, on the other, the performance of waterjet propulsion systems (for which this variable depends on the speed of the ship) has not been taken into account in any previous studies. This paper proposes that the efficiency of the propulsion system should be included as a new parameter in the equation that defines the actual power delivered by a ship's main engines, as applied to calculate energy consumption and emissions in maritime transport. To highlight the influence of the propulsion system on calculated energy consumption and emissions, the bottom-up method has been applied using data from eight fast ferries operating across the Strait of Gibraltar over the course of one year. This study shows that the uncertainty about the efficiency of the propulsion system should be added as one more uncertainty in the energy and emission inventories for maritime transport as currently prepared. After comparing four methods for this calculation, the authors propose a new method for eight cases. For the calculation of the Main Engine's fuel oil consumption, differences up to 22% between some methods were obtained at low loads. Copyright © 2018 Elsevier B.V. All rights reserved.

Statistical modelling for ship propulsion efficiency

DEFF Research Database (Denmark)

Petersen, Jóan Petur; Jacobsen, Daniel J.; Winther, Ole

2012-01-01

This paper presents a state-of-the-art systems approach to statistical modelling of fuel efficiency in ship propulsion, and also a novel and publicly available data set of high quality sensory data. Two statistical model approaches are investigated and compared: artificial neural networks...

Development of superconducting ship propulsion system

International Nuclear Information System (INIS)

Sakuraba, Junji; Mori, Hiroyuki; Hata, Fumiaki; Sotooka, Koukichi

1991-01-01

When we plan displacement-type monohull high speed vessels, it is difficult to get the hull form with the wave-making resistance minimum, because the stern shape is restricted by arrangement of propulsive machines and shafts. A small-sized and light-weight propulsive machines will reduce the limit to full form design. Superconducting technology will have capability of realizing the small-sized and light-weight propulsion motor. The superconducting electric propulsion system which is composed of superconducting propulsion motors and generators, seems to be an ideal propulsion system for future vehicles. We have constructed a 480 kW superconducting DC homopolar laboratory test motor for developing this propulsion system. The characteristic of this motor is that it has a superconducting field winding and a segmented armature drum. The superconducting field winding which operates in the persistent current mode, is cooled by a condensation heat exchanger and helium refigerating system built into the cryostat of the superconducting field winding. The operating parameters of this motor agreed well with the design parameters. Using the design concepts of this motor, we have conceptually designed a 150,000-200,000 PS superconducting electric propulsive system for a displacement-type monohull high speed ship. (author)

Pitch control for ships with diesel mechanical and hybrid propulsion : Modelling, validation and performance quantification

NARCIS (Netherlands)

Geertsma, R.D.; Negenborn, R.R.; Visser, K.; Loonstijn, M.A.; Hopman, J.J.

2017-01-01

Ships, in particular service vessels, need to reduce fuel consumption, emissions and cavitation noise while maintaining manoeuvrability and preventing engine overloading. Diesel mechanical propulsion with controllable pitch propellers can provide high fuel efficiency with good manoeuvrability.

Laddermill-sailing. Ship propulsion by wind energy independent from the wind direction

Energy Technology Data Exchange (ETDEWEB)

Ockels, W. J.

2007-12-15

The use of large kites in ship propulsion has been getting a growing attention because of the urgent need to reduce the CO2 production and thus stop the use of fossil fuels. A novel application of ship propulsion by kites is proposed based on a Laddermill apparatus mounted on a ship. Such an apparatus consist of a winch, an electric motor/generator, a kite system (including launch and retrieval) and controlling electronics. Rather than the traditional sailing by wind force the Laddermill propulsion is achieved by a combination of the production and use of electrical power and the direct pulling force from the kite system. The feasibility of this application is investigated. It is shown that when the overall Laddermill to ship thrust efficiency can be made around 50% the resulting speed of the ship becomes practically independent from the wind direction. Such a capability could thus well change the world's seafaring.

Prospects for applications of ship-propulsion nuclear reactors

International Nuclear Information System (INIS)

Mitenkov, F.M.

1994-01-01

The use of ship-propulsion nuclear power reactors in remote areas of Russia is examined. Two ship reactors were analyzed: the KLT-40, a 170 MW-thermal reactor; and the KN-3, a 300 MW-thermal reactor. The applications considered were electricity generation, desalination, and drinking water production. Analyses showed that the applications are technically justified and could be economically advantageous. 5 refs., 9 figs., 1 tab

Nuclear merchant ship propulsion. The present status in the UK

International Nuclear Information System (INIS)

Kinsey, R.P.

1976-01-01

The latest report of the Nuclear Ship Stearing Group which deals with three important aspects; economic assessments, international safety and operating procedures for nuclear ships, and the industrial capability of the UK shipbuilding and nuclear industries, is discussed. The integral design concept for a pressurised water reactor for use as a marine reactor is considered. The operational safety aspects of such reactors and of the attendant refuelling facilities are discussed. U.K. capability in the whole nuclear merchant ship propulsion project is considered; reference being made to the design and construction of small PWR reactors, the development, design and supply of the nuclear propulsion unit, financial aspects, and the requirement for cooperation between industrial interests and governmental research units. (U.K.)

Observer-based FDI for Gain Fault Detection in Ship Propulsion Benchmark

DEFF Research Database (Denmark)

Lootsma, T.F.; Izadi-Zamanabadi, Roozbeh; Nijmeijer, H.

2001-01-01

A geometric approach for input-affine nonlinear systems is briefly described and then applied to a ship propulsion benchmark. The obtained results are used to design a diagnostic nonlinear observer for successful FDI of the diesel engine gain fault......A geometric approach for input-affine nonlinear systems is briefly described and then applied to a ship propulsion benchmark. The obtained results are used to design a diagnostic nonlinear observer for successful FDI of the diesel engine gain fault...

Observer-based FDI for Gain Fault Detection in Ship Propulsion Benchmark

DEFF Research Database (Denmark)

Lootsma, T.F.; Izadi-Zamanabadi, Roozbeh; Nijmeijer, H.

2001-01-01

A geometric approach for input-affine nonlinear systems is briefly described and then applied to a ship propulsion benchmark. The obtained results are used to design a diagnostic nonlinear observer for successful FDI of the diesel engine gain fault.......A geometric approach for input-affine nonlinear systems is briefly described and then applied to a ship propulsion benchmark. The obtained results are used to design a diagnostic nonlinear observer for successful FDI of the diesel engine gain fault....

SALMON: an innovative concept of ship propulsion on rivers

NARCIS (Netherlands)

Wind, H.G.; Rotgers, A.

2001-01-01

In this paper a concept is studied, where the energy for the propulsion of a ship is extracted from the down flow of the river. In this concept three elements are important; a wire which is connected upstream, paddles on both sides of the ship and a drum which rotates due to the movement of the

Development of 1 MW-class HTS motor for podded ship propulsion system

Energy Technology Data Exchange (ETDEWEB)

Umemoto, K; Aizawa, K; Yokoyama, M; Yoshikawa, K [Kawasaki Heavy Industries LTD., 673-8666, Hyogo (Japan); Kimura, Y; Izumi, M [Tokyo University of Marine Science Technology, 135-8533, Tokyo (Japan); Ohashi, K; Numano, M [National Maritime Research Institute, 181-0004, Tokyo (Japan); Okumura, K; Yamaguchi, M; Gocho, Y; Kosuge, E, E-mail: umemoto@ati.khi.co.j [Japan Super-conductivity Organization Co. LTD., 135-8533, Tokyo (Japan)

2010-06-01

To reduce fuel consumption and lead to a major reduction of pollution from NOx, SOx and CO{sub 2}, the electric ship propulsion system is one of the most prospective substitutes for conventional ship propulsion systems. In order to spread it, innovative technologies for the improvement of the power transmission are required. The high temperature superconducting technology has the possibility for a drastic reduction of power transmission loss. Recently, electric podded propulsions have become popular for large cruise vessels, icebreakers and chemical tankers because of the flexibility of the equipment arrangement and the stern hull design, and better maneuverability in harbour, etc. In this paper, a 1 MW-class High temperature superconducting (HTS) motor with high efficiency, smaller size and simple structure, which is designed and manufactured for podded propulsion, is reported. For the case of a coastal ship driven by the optimized podded propulsion in which the 1MW HTS motor is equipped, the reductions of fluid dynamic resistance and power transmission losses are demonstrated. The present research and development has been supported by the New Energy and Industrial Technology Development Organization (NEDO).

Techno-economic investigation of alternative propulsion plants for Ferries and RoRo ships

International Nuclear Information System (INIS)

Livanos, George A.; Theotokatos, Gerasimos; Pagonis, Dimitrios-Nikolaos

2014-01-01

Highlights: • Alternative Diesel and Gas engine propulsion plants of Ferries and RoRos were studied. • Special focus on marine Natural Gas burning engines and ship waste heat recovery systems. • Significant savings in annual operating costs were predicted in the case of Natural Gas engines. • Environmental and economic optimum propulsion plant alternative was proposed in a specific case study. - Abstract: In this paper, the main alternative propulsion plants based on reciprocating internal combustion engines of a ferry or RoRo ship operating in routes that include Emission Control Areas (ECAs) are comparatively assessed. Specifically, a dual fuel engine propulsion plant is compared with a conventional Diesel engine plant. For both cases, the installation of a waste heat recovery system, which covers a part of the ship electric energy demand, is also considered. The ship main DF engines are assumed to operate using LNG and a small amount of MDO for initiating combustion, whereas low sulphur MDO was regarded as the fuel for the case of the Diesel engine plant. The installation of Selective Catalytic Reduction (SCR) after-treatment unit for reducing the NOx emissions for the case of Diesel engines plant is also taken into account. The propulsion plants were modelled under steady state conditions, and the simulation results were analysed in order to compare the alternative configurations. Furthermore, the Energy Efficiency Design Index (EEDI) values were calculated and the two examined propulsion system cases were compared on EEDI basis. Finally, the Life Cycle Cost for each alternative propulsion plant was calculated and used for completing an economic evaluation of the Dual fuel propulsion plant versus the conventional designs applied in ferries

Reconfigurable Control of a Ship Propulsion Plant

DEFF Research Database (Denmark)

Blanke, M.; Izadi-Zamanabadi, Roozbeh

1998-01-01

-tolerant control is a fairly new area. Thise paper presents a ship propulsion system as a benchmark that should be useful as a platform for the development of new ideas and a comparison of methods. The benchmark has two main elements. One is the development of efficient FDI algorithms, and the other...

Sensor Fault Masking of a Ship Propulsion System

DEFF Research Database (Denmark)

Wu, N.E.; Thavamani, A.; Zhang, Y.

2003-01-01

This paper presents the results of a study on fault-tolerant control of a ship propulsion benchmark (Izadi-Zamanabadi and Blanke, 1999), which uses estimated or virtual measurements as feedback variables. The estimator operates on a selfadjustable design model so that its outputs can be made immu...

Sensor Fault Masking of a Ship Propulsion System

DEFF Research Database (Denmark)

Wu, N. Eva; Thavamani, Shuda; Zhang, Youmin

2005-01-01

This paper presents the results of a study on fault-tolerant control of a ship propulsion benchmark (Izadi-Zamanabadi and Blanke, 999), which uses estimated or virtual measurements as feedback variables. The estimator operates on a self-adjustable design model so that its outputs can be made immu...

Propulsion of space ships by nuclear explosion

Science.gov (United States)

Linhart, J. G.; Kravárik, J.

2005-01-01

Recent progress in the research on deuterium-tritium (D-T) inertially confined microexplosions encourages one to reconsider the nuclear propulsion of spaceships based on the concept originally proposed in the Orion project. We discuss first the acceleration of medium-sized spaceships by D-T explosions whose output is in the range of 0.1 10 t of TNT. The launching of such a ship into an Earth orbit or beyond by a large nuclear explosion in an underground cavity is sketched out in the second section of the paper, and finally we consider a hypothetical Mars mission based on these concepts. In the conclusion it is argued that propulsion based on the Orion concept only is not the best method for interplanetary travel owing to the very large number of nuclear explosion required. A combination of a super gun and subsequent rocket propulsion using advanced chemical fuels appears to be the best solution for space flights of the near future.

Diesel fueled ship propulsion fuel cell demonstration project

Energy Technology Data Exchange (ETDEWEB)

Kumm, W.H. [Arctic Energies Ltd., Severna Park, MD (United States)

1996-12-31

The paper describes the work underway to adapt a former US Navy diesel electric drive ship as a 2.4 Megawatt fuel cell powered, US Coast Guard operated, demonstrator. The Project will design the new configuration, and then remove the four 600 kW diesel electric generators and auxiliaries. It will design, build and install fourteen or more nominal 180 kW diesel fueled molten carbonate internal reforming direct fuel cells (DFCs). The USCG cutter VINDICATOR has been chosen. The adaptation will be carried out at the USCG shipyard at Curtis Bay, MD. A multi-agency (state and federal) cooperative project is now underway. The USCG prime contractor, AEL, is performing the work under a Phase III Small Business Innovation Research (SBIR) award. This follows their successful completion of Phases I and II under contract to the US Naval Sea Systems (NAVSEA) from 1989 through 1993 which successfully demonstrated the feasibility of diesel fueled DFCs. The demonstrated marine propulsion of a USCG cutter will lead to commercial, naval ship and submarine applications as well as on-land applications such as diesel fueled locomotives.

Hybrid propulsion testing using direct-drive electrical machines for super yacht and inland shipping

NARCIS (Netherlands)

Paulides, J.J.H.; Djukic, N.; de Roon, J.A.; Encica, L.

2016-01-01

Hybrid or full electric propulsions for inland ships are becoming more popular. In these application, direct-drive PM propulsion motors are a preferred machine configuration. This paper discusses the challenges to determine the losses, as estimated with simulations, during the testing procedures of

Blowin' in the wind? Drivers and barriers for the uptake of wind propulsion in international shipping

International Nuclear Information System (INIS)

Rojon, Isabelle; Dieperink, Carel

2014-01-01

International shipping transports around 90% of global commerce and is of major importance for the global economy. Whilst it is the most efficient and environmentally friendly mode of transport, CO 2 emissions from shipping activities still account for an estimated 3% of global emissions. One means of significantly reducing fuel consumption and thereby GHG emissions from shipping are wind propulsion technologies (i.e. towing kites, Flettner rotors and sails) – yet current market uptake is very low. Therefore, the aim of this article is to identify the barriers and drivers for the uptake of wind propulsion technologies. To this end, the theoretical approach of technological innovation systems is adopted. This approach combines structural system components with so-called system functions which represent the dynamics underlying structural changes in the system. The fulfillment of these functions is considered important for the development and diffusion of innovations. Based on newspaper and academic articles, online expert interviews and semi-structured interviews, the level of function fulfillment is evaluated, followed by the identification of structural drivers and barriers influencing function fulfillment. Third, the possibilities to influence these drivers and barriers are discussed. - Highlights: • The overall performance of the technological innovation system for wind propulsion technologies is low. • Experts acknowledge the importance, but also the lack of fulfillment of theoretically relevant innovation functions. • Structural barriers for the development of wind propulsion technologies outweigh drivers. • Drivers for the development of wind propulsion technologies are only emerging while barriers have existed for a long time. • The IMO can stimulate knowledge development and diffusion as well as the development of market-based instruments

Structural modeling and fuzzy-logic based diagnosis of a ship propulsion benchmark

DEFF Research Database (Denmark)

Izadi-Zamanabadi, Roozbeh; Blanke, M.; Katebi, S.D.

2000-01-01

An analysis of structural model of a ship propulsion benchmark leads to identifying the subsystems with inherent redundant information. For a nonlinear part of the system, a Fuzzy logic based FD algorithm with adaptive threshold is employed. The results illustrate the applicability of structural...

Natural gas for ship propulsion in Denmark - Possibilities for using LNG and CNG on ferry and cargo routes

Energy Technology Data Exchange (ETDEWEB)

Stuer-Lauridsen, F.; Nielsen, Jesper B. (LITEHAUZ, Copenhagen (Denmark)); Odgaard, T.; Birkeland, M. (IncentivePartners, Birkeroed (Denmark)); Winter Graugaard, C.; Blikom, L.P. (DNV, Copenhagen (Denmark)); Muro-Sun, N.; Andersen, Morten; OEvlisen, F. (Ramboell Oil and Gas, Esbjerg (Denmark))

2010-07-01

The project's main task was to review logistical, technical and economic feasibility for using Liquefied Natural Gas (LNG) and Compressed Natural Gas (CNG) as fuel for ship propulsion and the supply of LNG or CNG to Danish ports from existing natural gas lines, trucks or by ship. The following key findings are related to the use of natural gas as fuel for ships in Denmark: Natural gas as propulsion fuel in ships: 1) Advantages: Provide solution to present air emission challenges 2) Barriers: Capital investments large 3) Synergies: Developments in Norway and Baltic Sea area 4) Economy: Positive case for operation for large consumers 5) Future: Develop bunkering options for short sea shipping LNG: 6) Propulsion technology in ships is mature and proven 7) Distribution network not yet developed for use in ships 8) Safety concerns are demanding but manageable 9) Can enter existing bunkering value chain CNG: 10) Well developed for land based transport, not yet for shipping 11) Distribution network for natural gas exists in Denmark 12) Safety concerns are demanding but manageable 13) No seaborne CNG value chains in operation An immediate focus on the ferry sector in Denmark will reap benefits on a relatively short time scale. For the short sea shipping sector away to promote the conversion to natural gas is to support the development of storage and bunkering facilities in main ports. Given the general expectations in the shipping community LNG will presumably be the de facto choice at least for the 5-10 years ahead and the demand for facilities and bunkers will be for LNG. (LN)

Thermal-hydraulic transient characteristics of ship-propulsion reactor investigated through safety analysis

International Nuclear Information System (INIS)

Fujiki, Kazuo; Asaka, Hideaki; Ishida, Toshihisa

1986-01-01

Thermal-hydraulic behaviors in the reactor of Nuclear Ship ''Mutsu'' were investigated through safety evaluation of operational transients by using RETRAN and COBRA-IV codes. The results were compared to the transient behaviors of typical commercial PWR and the characteristics of transient thermal-hydraulic behaviors in ship-loaded reactor were figured out. ''Mutsu'' reactor has larger thermal margin than commercial PWR because it is designed to be used as ship-propulsion power source in the load-following operation mode. This margin makes transient behavior in general milder than in commercial PWR but high opening pressure set point of main-steam safety valves leads poor heat-sink condition after reactor trip. The effects of other small-sized components are also investigated. The findings in the paper will be helpful in the design of future advanced reactor for nuclear ship. (author)

DISCRETION MAGNETIQUE DES MACHINES ELECTRIQUES DE PROPULSION NAVALE

OpenAIRE

Froidurot , Benoît

2002-01-01

For about ten years, electrical machines have been commonly used in naval propulsion systems for civilian applications. This is mainly due to new magnetic materials (magnets...) and power drive electronic, which increase the performances of the machines. This kind of propulsion is planed to be implemented on military ships. However, some constraints of discretion make this propulsion require specific systems for the ship security. This study is then dedicted to the magnetic discretion of nava...

Analysis of Electric Propulsion Performance on Submersible with Motor DC, Supply Power 10260AH at Voltage 115VDC

Directory of Open Access Journals (Sweden)

Indra Ranu Kusuma

2017-03-01

Full Text Available Electric propulsion is the ship system using propulsion motor to replace performance of main engine. The application of diesel engine as propulsion system have some problems and weaknesses such as diesel engine unability to operate when submersible vessel is operating under sea. To overcome that problems in submersible vessel, alternative solution of ship propulsion is required. DC Motor can be used as this alternative solution. Submersible vessel use electric propulsion system with DC Motor because DC Motor has advantages of easy rotation setting and does not cause noise when submersible vessel is diving. This bachelor thesis will study the application of DC Motor as an electric propulsion system on submersible vessel with length 59,57 m in series and parallel circuit by simulation using MATLAB software. The simulation data obtained are rotation and torque of DC Motor. From these simulation, it can be concluded that parallel circuit rotation is greater than series circuit rotation. It caused the greater speed and lower power in parallel circuit. 

Case Study on the Unavailability of a Ship Propulsion System under Aging Effects and Maintenance

OpenAIRE

Tadatsugi Okazaki

2016-01-01

Unavailability of a ship propulsion system under aging effects and proper maintenance is estimated using GO-FLOW. GO-FLOW is an effective software tool for the unavailability analysis of complex systems. Aging effects are incorporated into GO-FLOW using a time-dependent technique and assuming a linear aging model. The results show that the aging effects and improper maintenance can potentially increase the frequency of accidents due to a malfunction of the propulsion system by a factor of three.

The SMPR for the naval propulsion; Les RPMP pour la propulsion navale

Energy Technology Data Exchange (ETDEWEB)

Gauducheau, B. [Technicatome, Centre d' Etudes Nucleaires de Saclay, 91 - Gif sur Yvette (France)

2002-07-01

The first controlled application of the fissile energy was the american nuclear reactor for the ship propulsion. Since the sixties, the France begun researches to secure the independence of its nuclear propulsion program. The historical aspects, the french program management and the perspectives of the ship nuclear propulsion, are discussed in this paper. (A.L.B.)

Performance of Ships and Offshore Structures in Waves

Directory of Open Access Journals (Sweden)

Shukui Liu

2012-01-01

for predicting large amplitude motions of ships and floating structures in response to incoming waves in the frame of potential theory. The developed alternative set of time domain methods simulate the hydrodynamic forces acting on ships advancing in waves with constant speed. For motions’ simulation, the diffraction forces and radiation forces are calculated up to the mean wetted surface, while the Froude-Krylov forces and hydrostatic restoring forces are calculated up to the undisturbed incident wave surface in case of large incident wave amplitude. This enables the study of the above waterline hull form effect. Characteristic case studies on simulating the hydrodynamic forces and motions of standard type of ships have been conducted for validation purpose. Good agreement with other numerical codes and experimental data has been observed. Furthermore, the added resistance of ships in waves can be calculated by the presented methods. This capability supports the increased demand of this type of tools for the proper selection of engine/propulsion systems accounting for ship’s performance in realistic sea conditions, or when optimizing ship’s sailing route for minimum fuel consumption and toxic gas emissions.

Dynamic simulator for PEFC propulsion plant

Energy Technology Data Exchange (ETDEWEB)

Hiraide, Masataka; Kaneda, Eiichi; Sato, Takao [Mitsui Engineering & Shipbuilding Co., Ltd., Tokyo (Japan)] [and others

1996-12-31

This report covers part of a joint study on a PEFC propulsion system for surface ships, summarized in a presentation to this Seminar, entitled {open_quote}Study on a Polymer Electrolyte Fuel Cell (PEFC) Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The work presented here focuses on a simulation study on PEFC propulsion plant performance, and particularly on the system response to changes in load. Using a dynamic simulator composed of system components including fuel cell, various simulations were executed, to examine the performance of the system as a whole and of the individual system components under quick and large load changes such as occasioned by maneuvering operations and by racing when the propeller emerges above water in heavy sea.

Vertical-axis turbine/propeller for ship propulsion

Energy Technology Data Exchange (ETDEWEB)

Barkla, H.M.

1984-01-01

There are so many variables in the design and operating conditions of a vertical-axis turbine/propeller for the propulsion of a ship by wind that a preliminary study is offered, based on two simplified models. Study of a linear motion of blades in air and water shows optimum conditions for blade-speed and blade-incidence. Analysis of the second, cyclical model is simplified by the assumption of constant angles of incidence. While the logical superiority of the vertical-axis system, with its low transmission loss, may not alone give it the advantage over all other systems in upwind and downwind sailing, there are indications that in the beam wind it is in a class of its own; the Voith-Schneider-Type propeller then produces a thrust with a major component to windward, so that the combined unit leaves little or no athwartships force.

Study of Green Shipping Technologies - Harnessing Wind, Waves and Solar Power in New Generation Marine Propulsion Systems

Directory of Open Access Journals (Sweden)

Grzegorz Rutkowski

2016-12-01

Full Text Available The purpose and scope of this paper is to describe the complexity of the new generation marine propulsion technologies implemented in the shipping industry to promote green ships concept and change the view of sea transportation to a more ecological and environment-friendly. Harnessing wind, waves and solar power in shipping industry can help the ship’s owners reduce the operational costs. Reducing fuel consumption results in producing less emissions and provides a clean source of renewable energy. Green shipping technologies can also effectively increase the operating range of vessels and help drive sea transportation towards a greener future and contribute to the global reduction of harmful gas emissions from the world's shipping fleets.

Introduction to the 'CAS' nuclear propulsion plant for ships: specific safety options

International Nuclear Information System (INIS)

Verdeau, J.J.; Baujat, J.

1978-01-01

After a brief review of the development of nuclear propulsion in FRANCE (Land Based Prototype PAT 1964 - Navy nuclear ships - Advanced Nuclear Boiler Prototype CAP 1975 and now the CAS nuclear plant), the specific safety options of CAS are presented: cold, compartmented fuel (plates); reduced flow during LOCA; permanent cooling of fuel during LOCA; pressurized, entirely passive containment; no control rod ejection and possibility of temporary storage of spent fuel on board [fr

Modelling the Dynamics of Ships with Different Propulsion Systems for Control Purpose

Directory of Open Access Journals (Sweden)

Gierusz Witold

2016-01-01

Full Text Available Two different propulsion systems are analyzed from point of view of future control applications. The traditional one consists of a pushing single screw propeller and a blade rudder. The other system is based on pod (pods: pulling or pushing ones. The equations describing forces and moments generated in both systems, are presented. Exemplary results of a simulation in comparison to the real-time experiments for two ships are also shown.

Recent progress in the NDE of cast ship propulsion components

Science.gov (United States)

Spies, Martin; Rieder, Hans; Dillhöfer, Alexander; Rauhut, Markus; Taeubner, Kai; Kreier, Peter

2014-02-01

The failure of propulsion components of ships and ferries can lead to serious environmental and economic damage or even the loss of lives. For ultrasonic inspection of such large components we employ mechanized scanning and defect reconstruction using the Synthetic Aperture Focusing Technique (SAFT). We report on results obtained in view of the detection of defects with different inspection techniques. Also, we address the issue of Probability of Detection by reporting results obtained in POD and MAPOD-studies (Model-Assisted POD) using experimental and simulated data. Finally, we show recent results of surface and sub-surface inspection using optical and eddy current techniques.

Shield design development of nuclear propulsion merchant ship

International Nuclear Information System (INIS)

Tanaka, Yoshihisa

1975-01-01

Shielding design both in Japan and abroad for nuclear propulsion merchant ships is explained, with emphasis on the various technological problems having occurred in the shield design for one-body type and separate type LWRs as conceptual design. The following matters are described: the peculiarities of the design as compared with the case of land-based nuclear reactors, problems in the design standards of shielding, the present status and development of the design methods, and the instances of the design; thereby, the trends of shielding design are disclosed. The following matters are pointed out: Importance of the optimum design, of shielding, significance of radiation streaming through large voids, activation of the secondary water in built-in type steam generators, and the need of the guides for shield design. (Mori, K.)

Sensorless control of ship propulsion interior permanent magnet synchronous motor based on a new sliding mode observer.

Science.gov (United States)

Ren, Jun-Jie; Liu, Yan-Cheng; Wang, Ning; Liu, Si-Yuan

2015-01-01

This paper proposes a sensorless speed control strategy for ship propulsion interior permanent magnet synchronous motor (IPMSM) based on a new sliding-mode observer (SMO). In the SMO the low-pass filter and the method of arc-tangent calculation of extended electromotive force (EMF) or phase-locked loop (PLL) technique are not used. The calculation of the rotor speed is deduced from the Lyapunov function stability analysis. In order to reduce system chattering, sigmoid functions with switching gains being adaptively updated by fuzzy logic systems are innovatively incorporated into the SMO. Finally, simulation results for a 4.088 MW ship propulsion IPMSM and experimental results from a 7.5 kW IPMSM drive are provided to verify the effectiveness of the proposed SMO method. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

A high temperature reactor for ship propulsion

International Nuclear Information System (INIS)

Lobet, P.; Seigel, R.; Thompson, A.C.; Beadnell, R.M.; Beeley, P.A.

2002-01-01

The initial thermal hydraulic and physics design of a high temperature gas cooled reactor for ship propulsion is described. The choice of thermodynamic cycle and thermal power is made to suit the marine application. Several configurations of a Helium cooled, Graphite moderated reactor are then analysed using the WIMS and MONK codes from AEA Technology. Two geometries of fuel elements formed using micro spheres in prismatic blocks, and various arrangements of control rods and poison rods are examined. Reactivity calculations through life are made and a pattern of rod insertion to flatten the flux is proposed and analysed. Thermal hydraulic calculations are made to find maximum fuel temperature under high power with optimized flow distribution. Maximum temperature after loss of flow and temperatures in the reactor vessel are also computed. The temperatures are significantly below the known limits for the type of fuel proposed. It is concluded that the reactor can provide the required power and lifetime between refueling within likely space and weight constraints. (author)

Nuclear ships and their safety

Energy Technology Data Exchange (ETDEWEB)

NONE

1961-04-15

Several aspects of nuclear ship propulsion, with special reference to nuclear safety, were discussed at an international symposium at Taormina, Italy, from 14-18 November 1960. Discussions on specific topics are conducted, grouped under the following headings: Economics and National Activities in Nuclear Ship Propulsion; International Problems and General Aspects of Safety for Nuclear Ships; Nuclear Ship Projects from the Angle of Safety; Ship Reactor Problems; Sea Motion and Hull Problems; Maintenance and Refuelling Problems; and Safety Aspects of Nuclear Ship Operation.

Hybrid shipping for inland navigation : loss analysis of an aluminum direct-drive high performance 11,OOONm permanent magnet machine

NARCIS (Netherlands)

Paulides, J.J.H.; Djukic, N.; Encica, L.

2015-01-01

Hybrid electric ship propulsions are becoming a leading/emerging area of research, prompting investigation in hybrid propulsion system design and demonstration of concept vessels. With respect to ship design and operation, minimizing costs associated with fuel consumption and maintenance are key

Fuel Cycle Cost Calculations for a 120,000 shp PWR for Ship Propulsion. RCN Report

International Nuclear Information System (INIS)

Dekker, N.H.; Foggi, C.; Giacomazzi, G.

1972-02-01

A parametric study of the fuel cycle costs for a 120,000 SHP PWR for ship propulsion has been carried out. Variable parameters are: fuel pellet diameter, moderating ratio and refuelling scheme. Minimum fuel cycle costs can be obtained at moderating ratios of about 2.2. Both fuel cycle costs and reactor control requirements favour the two batch core. (author)

MODELING OF OPERATION MODES OF SHIP POWER PLANT OF COMBINED PROPULSION COMPLEX WITH CONTROL SYSTEM BASED ON ELECTRONIC CONTROLLERS

Directory of Open Access Journals (Sweden)

E. A. Yushkov

2016-12-01

Full Text Available Purpose. Designing of diagrams to optimize mathematic model of the ship power plant (SPP combined propulsion complexes (CPC for decreasing operational loss and increasing fuel efficiency with simultaneous load limiting on medium revolutions diesel generator (MRDG by criterion reducing of wear and increasing operation time between repairs. Methodology. After analyzing of ship power plant modes of CPC proposed diagrams to optimize mathematic model of the above mentioned complex. The model based on using of electronic controllers in automatic regulation and control systems for diesel and thruster which allow to actualize more complicated control algorithm with viewpoint of increasing working efficiency of ship power plant at normal and emergency modes. Results. Determined suitability of comparative computer modeling in MatLab Simulink for building of imitation model objects based on it block diagrams and mathematic descriptions. Actualized diagrams to optimize mathematic model of the ship’s power plant (SPP combined propulsion complexes (CPC with Azipod system in MatLab Simulink software package Ships_CPC for decreasing operational loss and increasing fuel efficiency with simultaneous load limiting on medium revolutions diesel generator (MRDG by criterion reducing of wear and increasing operation time between repairs. The function blocks of proposed complex are the main structural units which allow to investigate it normal and emergency modes. Originality. This model represents a set of functional blocks of the components SPP CPC, built on the principle of «input-output». For example, the function boxes outputs of PID-regulators of MRDG depends from set excitation voltage and rotating frequency that in turn depends from power-station load and respond that is a ship moving or dynamically positioning, and come on input (inputs of thruster rotating frequency PID-regulator models. Practical value. The results of researches planned to use in

Dimensionless Numerical Approaches for the Performance Prediction of Marine Waterjet Propulsion Units

Directory of Open Access Journals (Sweden)

Marco Altosole

2012-01-01

Full Text Available One of the key issues at early design stage of a high-speed craft is the selection and the performance prediction of the propulsion system because at this stage only few information about the vessel are available. The objective of this work is precisely to provide the designer, in the case of waterjet propelled craft, with a simple and reliable calculation tool, able to predict the waterjet working points in design and off-design conditions, allowing to investigate several propulsive options during the ship design process. In the paper two original dimensionless numerical procedures, one referred to jet units for naval applications and the other more suitable for planing boats, are presented. The first procedure is based on a generalized performance map for mixed flow pumps, derived from the analysis of several waterjet pumps by applying similitude principles of the hydraulic machines. The second approach, validated by some comparisons with current waterjet installations, is based on a complete physical approach, from which a set of non-dimensional waterjet characteristics has been drawn by the authors. The presented application examples show the validity and the degree of accuracy of the proposed methodologies for the performance evaluation of waterjet propulsion systems.

Light UAV Support Ship (ASW) (LUSSA)

Science.gov (United States)

2011-08-01

Propeller EMALS - Electromagnetic Aircraft Launch System GM - Center of Gravity to Metacenter HFO - Heavy Fuel Oil IPS - Integrated Propulsion System...it induces high cavitation levels on surface ships. The ship’s final design implemented a contra- rotating propeller (CRP) system. CRP propulsion...Stability Analyses Intact stability analyses were performed using the hydrodynamic modeling tool Paramarine. The vertical center of gravity (VCG) of

A Step by Step Approach for Evaluating the Reliability of the Main Engine Lube Oil System for a Ship's Propulsion System

Directory of Open Access Journals (Sweden)

Mohan Anantharaman

2014-09-01

Full Text Available Effective and efficient maintenance is essential to ensure reliability of a ship's main propulsion system, which in turn is interdependent on the reliability of a number of associated sub- systems. A primary step in evaluating the reliability of the ship's propulsion system will be to evaluate the reliability of each of the sub- system. This paper discusses the methodology adopted to quantify reliability of one of the vital sub-system viz. the lubricating oil system, and development of a model, based on Markov analysis thereof. Having developed the model, means to improve reliability of the system should be considered. The cost of the incremental reliability should be measured to evaluate cost benefits. A maintenance plan can then be devised to achieve the higher level of reliability. Similar approach could be considered to evaluate the reliability of all other sub-systems. This will finally lead to development of a model to evaluate and improve the reliability of the main propulsion system.

Fault detection for piecewise affine systems with application to ship propulsion systems.

Science.gov (United States)

Yang, Ying; Linlin, Li; Ding, Steven X; Qiu, Jianbin; Peng, Kaixiang

2017-09-09

In this paper, the design approach of non-synchronized diagnostic observer-based fault detection (FD) systems is investigated for piecewise affine processes via continuous piecewise Lyapunov functions. Considering that the dynamics of piecewise affine systems in different regions can be considerably different, the weighting matrices are used to weight the residual of each region, so as to optimize the fault detectability. A numerical example and a case study on a ship propulsion system are presented in the end to demonstrate the effectiveness of the proposed results. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

Propulsive efficiency and non- expert swimmers performance

Directory of Open Access Journals (Sweden)

Tiago Barbosa

2009-12-01

Full Text Available Propulsive efficiency is one of the most interesting issues for competitive swimming researchers, has it presents significant relationships with the swimmer’s biophysical behavior and his/her performance. Although propulsive efficiency is a variable that has been quite studied in elite swimmers, there is no research on this issue in young and non-expert swimmers. Thus, the aim of this study was to: (i estimate the propulsive efficiency on non-expert swimmers; (ii identify biomechanical and anthropometrical parameters that are associated with propulsive efficiency; (iii identify the association between the propulsive efficiency and swim performance. Twenty-eight non-expert swimmers participated on this study. It was assessed the propulsive efficiency, biomechanical and anthropometrical parameters, as well as, the swim performance. The propulsive efficiency of non-expert swimmers is lower than data reported in the literature to higher competitive levels swimmers and there are no significant differences between boys and girls. It was also noted that several biomechanical and anthropometrical parameters, as well as, the swim performance are associated with the propulsive efficiency.

Numerical simulation of the flow around a steerable propulsion unit

International Nuclear Information System (INIS)

Pacuraru, F; Lungu, A; Ungureanu, C; Marcu, O

2010-01-01

Azimuth propulsion units have become during the last decade a more and more popular solution for all kinds of vessels. Azimuth thruster system, combining the propulsion and steering units of conventional ships replaces traditional propellers and lengthy drive shafts and rudders ensuring an excellent vessel steering. In many cases the interaction between the propeller and other components of the propulsion system strongly affects the inflow to the propeller and therefore its performance. The correct estimation of this influence is important for propulsion systems which consist of more than one element, such as pods (shaft, gondola and propeller), ducted propellers (duct, struts and propeller) or bow thrusters (ship form, tunnel, gondola and propeller). The paper proposes a numerical investigation based on RANS computation for solving the viscous flow around an azimuth thruster system to provide a detailed insight into the critical flow regions for determining the optimum inclination angle for struts, for studying the hydrodynamic interactions between various components of the system, for predicting the hydrodynamic performance of the propulsion system and to investigate regions with possible flow separations.

46 CFR 109.555 - Propulsion boilers.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion boilers. 109.555 Section 109.555 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) A-MOBILE OFFSHORE DRILLING UNITS OPERATIONS Miscellaneous § 109.555 Propulsion boilers. The master or person in charge and the engineer in charge shall...

46 CFR 130.120 - Propulsion control.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion control. 130.120 Section 130.120 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) OFFSHORE SUPPLY VESSELS VESSEL CONTROL, AND MISCELLANEOUS EQUIPMENT AND SYSTEMS Vessel Control § 130.120 Propulsion control. (a) Each vessel must have— (1...

A cermet fuel reactor for nuclear thermal propulsion

International Nuclear Information System (INIS)

Kruger, G.

1991-01-01

Work on the cermet fuel reactor done in the 1960's by General Electric (GE) and the Argonne National Laboratory (ANL) that had as its goal the development of systems that could be used for nuclear rocket propulsion as well as closed cycle propulsion system designs for ship propulsion, space nuclear propulsion, and other propulsion systems is reviewed. It is concluded that we can have excellent thermal and mechanical performance with cermet fuel. Thousands of hours of testing were performed on the cermet fuel at both GE and AGL, including very rapid transients and some radiation performance history. We conclude that there are no feasibility issues with cermet fuel. What is needed is reactivation of existing technology and qualification testing of a specific fuel form. We believe this can be done with a minimum development risk

A cermet fuel reactor for nuclear thermal propulsion

Science.gov (United States)

Kruger, Gordon

1991-01-01

Work on the cermet fuel reactor done in the 1960's by General Electric (GE) and the Argonne National Laboratory (ANL) that had as its goal the development of systems that could be used for nuclear rocket propulsion as well as closed cycle propulsion system designs for ship propulsion, space nuclear propulsion, and other propulsion systems is reviewed. It is concluded that the work done in the 1960's has demonstrated that we can have excellent thermal and mechanical performance with cermet fuel. Thousands of hours of testing were performed on the cermet fuel at both GE and AGL, including very rapid transients and some radiation performance history. We conclude that there are no feasibility issues with cermet fuel. What is needed is reactivation of existing technology and qualification testing of a specific fuel form. We believe this can be done with a minimum development risk.

Results from a large-scale MHD propulsion experiment

International Nuclear Information System (INIS)

Petrick, M.; Libera, J.; Bouillard, J.X.; Pierson, E.S.; Hill, D.

1992-01-01

This paper reports on magnetohydrodynamic (MHD) thrusters which have long been recognized as potentially attractive candidates for ship propulsion because such systems eliminate the conventional rotating drive components. The MHD thruster is essentially an electromagnet (EM) pump operating in seawater. An electrical current is passed directly through the seawater and interacts with an applied magnetic field; the interaction of the magnetic field and the electrode current in the seawater results in a Lorentz force acting on the water, and the reaction to this force propels the vessel forward. The concept of EM propulsion has been examined periodically during the past 35 years as an alternative method of propulsion for surface ships and submersibles. The conclusions reached in early studies were that MHD thrusters restricted to fields of 2T (the state-of-the-art at that time) were impractical and very inefficient. With the evolution of superconducting magnet technology, later studies investigated the performance of MHD thrusters with much higher magnetic field strengths and concluded that at higher fields (>6 T) practical MHD propulsion systems appear possible

Performance Monitoring of Ships

DEFF Research Database (Denmark)

Hansen, Søren Vinther

is used as input to the system and by comparing model and ship behaviour, an index describing the ship’s performance is generated. The work in this thesis is based on data logged through the automation system on board a PostPanmax container ship where data have been logged through a year. A routine...... in the models have been identified. The models used in this work are based on empirical relations or based on regression analyses of model tests and full-scale trials. In order to achieve valid results the conditions where performance is estimated have to be inside the boundaries of the model. Filters have been......The purpose of the research project is to establish a reliable index in the performance evaluation of ships. During operation the ship will experience added resistance due to fouling of hull and propeller. The added resistance will lead to increased fuel consumption and thus increased emissions...

Civilian nuclear ships

International Nuclear Information System (INIS)

Oelgaard, P.L.

1993-03-01

This report contains a review of the information available on nuclear powered ships, built for civilian purposes. In the introduction a short discussion is given of the reasons for the limited use of nuclear ships for these purposes. In the second section a brief review is presented of data for the three experimental/merchant ships build by the United States, Germany and Japan, i.e. NS Savannah, NS Otto Hahn and NS Mutsu. In the third section the Soviet/Russian icebreaker NS Lenin is considered. Its design, operational experience and the introduction of a new nuclear propulsion plant is reviewed. In the fourth section the newer Soviet/Russian icebreakers with nuclear propulsion are considered. Finally design of the Soviet/Russian icebreaker transport/container ship NS Sevmorput is reviewed in the fifth section. The future Russian plans for nuclear vessels for the arctic waters are briefly discussed. (au)

The Study about Application of Transportation System of the Superconductive Electromagnetism Propulsion in the Harbor

OpenAIRE

涌井, 和也; 荻原, 宏康

1999-01-01

Electromagnetic propulsion is promising technique for a linear motor car, a ship and a space ship, in future. W. A Rice developed an electromagnetic pump for the liquid metal transfer. There are two electromagnetic propulsions : a superconductive electricity propulsion and a superconductive electromagnetic propulsion. A superconductive electricity propulsion ship uses a screw driven by a superconducting motor. This technique has merits of excellent navigation-ability, and the free degree of t...

Comparison of Aero-Propulsive Performance Predictions for Distributed Propulsion Configurations

Science.gov (United States)

Borer, Nicholas K.; Derlaga, Joseph M.; Deere, Karen A.; Carter, Melissa B.; Viken, Sally A.; Patterson, Michael D.; Litherland, Brandon L.; Stoll, Alex M.

2017-01-01

NASA's X-57 "Maxwell" flight demonstrator incorporates distributed electric propulsion technologies in a design that will achieve a significant reduction in energy used in cruise flight. A substantial portion of these energy savings come from beneficial aerodynamic-propulsion interaction. Previous research has shown the benefits of particular instantiations of distributed propulsion, such as the use of wingtip-mounted cruise propellers and leading edge high-lift propellers. However, these benefits have not been reduced to a generalized design or analysis approach suitable for large-scale design exploration. This paper discusses the rapid, "design-order" toolchains developed to investigate the large, complex tradespace of candidate geometries for the X-57. Due to the lack of an appropriate, rigorous set of validation data, the results of these tools were compared to three different computational flow solvers for selected wing and propulsion geometries. The comparisons were conducted using a common input geometry, but otherwise different input grids and, when appropriate, different flow assumptions to bound the comparisons. The results of these studies showed that the X-57 distributed propulsion wing should be able to meet the as-designed performance in cruise flight, while also meeting or exceeding targets for high-lift generation in low-speed flight.

Waves from Propulsion Systems of Fast Ferries

DEFF Research Database (Denmark)

Taatø, Søren Haugsted; Aage, Christian; Arnskov, Michael M.

1998-01-01

Waves from fast ferries have become an environmental problem of growing concern to the public. Fast ferries produce not only higher waves than conventional ships but also fundamentally different wave systems when they sail at supercritical speeds. Hitherto, ship waves have been considered as being...... generated by the ship hulls alone. Whereas this assumption may be reasonable for conventional ships with large hulls and limited propulsive power, the situation is different for fast ferries with their smaller hulls and very large installed power. A simple theoretical model and a series of model tests...... on a monohull fast ferry seem to indicate that a substantial part of the wave-making can be directly attributed to the propulsion system itself. Thus, two wave systems are created with different phases, but with similar frequency contents, which means that they merge into one system behind the ship, very...

Effects of ship's vibration and motion on plant parameters

International Nuclear Information System (INIS)

Kakuta, Tsunemi; Kitamura, Toshikatsu; Mizushima, Toshihiko; Yamazaki, Hiroshi; Nakahara, Takeshi; Kamiya, Eisei; Kudou, Takahiro; Naitoh, Akira; Tominaga, Mineo.

1992-03-01

Present report was written about the study of the effects of ship's vibration and motion on reactor plant performances measured and analyzed to confirm the total balance for control systems of reactor to propulsion. On July 10, 1990, or on the first day of the first voyage for the power up test, the sea trials of MUTSU, nuclear ship made first in Japan, started from the anchoring test. The trial tests had finished through the third voyage between October 30 and November 9 to the fourth voyage between 7 and 14 of December. The trial tests had been conducted over ten items or so containing in-house tests of the measurements of ship's vibration and motion in order to research the effects on reactor performance. We here call the in-house tests the plant correlation tests. In regard to the correlation with ship's vibration, we confirmed that the inherent vibrations of hull and reactor containment arisen from ship structure had precisely been measured and that the plant correlations due to the hull and local vibrations arising from propeller revolutions are very small. Concerning the correlation with ship's motion, it was shown that her rolling motion strongly had affected on the propulsion system such as shaft power and shaft revolutions. About the correlation with reactor systems it was found that her pitching motion had given effect on the water level in pressurizer, primary coolant average temperature, ε-signal of the auto-control of reactor power and primary coolant pressure etc, particularly, most-strongly on the water level in pressurizer; her rolling and pitching motions had given effect on nuclear characteristics such as reactivity and startup rate; in addition the fluctuation of 0.06 Hz, we think the response inherent in (MUTSU) reactor systems, had been observed on her reactor parameters like reactivity and startup rate, and her propulsion systems like shaft horse power. (author)

Magnetic levitation and MHD propulsion

International Nuclear Information System (INIS)

Tixador, P.

1994-01-01

Magnetic levitation and MHD propulsion are now attracting attention in several countries. Different superconducting MagLev and MHD systems will be described concentrating on, above all, the electromagnetic aspect. Some programmes occurring throughout the world will be described. Magnetic levitated trains could be the new high speed transportation system for the 21st century. Intensive studies involving MagLev trains using superconductivity have been carried our in Japan since 1970. The construction of a 43 km long track is to be the next step. In 1991 a six year programme was launched in the United States to evaluate the performances of MagLev systems for transportation. The MHD (MagnetoHydroDynamic) offers some interesting advantages (efficiency, stealth characteristics, ..) for naval propulsion and increasing attention is being paid towards it nowadays. Japan is also up at the top with the tests of Yamato I, a 260 ton MHD propulsed ship. (orig.)

Magnetic levitation and MHD propulsion

Energy Technology Data Exchange (ETDEWEB)

Tixador, P [CNRS/CRTBT-LEG, 38 - Grenoble (France)

1994-04-01

Magnetic levitation and MHD propulsion are now attracting attention in several countries. Different superconducting MagLev and MHD systems will be described concentrating on, above all, the electromagnetic aspect. Some programmes occurring throughout the world will be described. Magnetic levitated trains could be the new high speed transportation system for the 21st century. Intensive studies involving MagLev trains using superconductivity have been carried our in Japan since 1970. The construction of a 43 km long track is to be the next step. In 1991 a six year programme was launched in the United States to evaluate the performances of MagLev systems for transportation. The MHD (MagnetoHydroDynamic) offers some interesting advantages (efficiency, stealth characteristics, ..) for naval propulsion and increasing attention is being paid towards it nowadays. Japan is also up at the top with the tests of Yamato I, a 260 ton MHD propulsed ship. (orig.).

46 CFR 121.620 - Propulsion engine control systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Propulsion engine control systems. 121.620 Section 121... Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of shaft rotation, and engine...

46 CFR 184.620 - Propulsion engine control systems.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Propulsion engine control systems. 184.620 Section 184... Communications Systems § 184.620 Propulsion engine control systems. (a) A vessel must have two independent means of controlling each propulsion engine. Control must be provided for the engine speed, direction of...

Thermodynamic analysis of a dual loop heat recovery system with trilateral cycle applied to exhaust gases of internal combustion engine for propulsion of the 6800 TEU container ship

International Nuclear Information System (INIS)

Choi, Byung Chul; Kim, Young Min

2013-01-01

A dual loop waste heat recovery power generation system that comprises an upper trilateral cycle and a lower organic Rankine cycle, in which discharged exhaust gas heat is recovered and re-used for propulsion power, was theoretically applied to an internal combustion engine for propulsion in a 6800 TEU container ship. The thermodynamic properties of this exhaust gas heat recovery system, which vary depending on the boundary temperature between the upper and lower cycles, were also investigated. The results confirmed that this dual loop exhaust gas heat recovery power generation system exhibited a maximum net output of 2069.8 kW, and a maximum system efficiency of 10.93% according to the first law of thermodynamics and a maximum system exergy efficiency of 58.77% according to the second law of thermodynamics. In this case, the energy and exergy efficiencies of the dual loop system were larger than those of the single loop trilateral cycle. Further, in the upper trilateral cycle, the volumetric expansion ratio of the turbine could be considerably reduced to an adequate level to be employed in the practical system. When this dual loop exhaust gas heat recovery power generation system was applied to the main engine of the container ship, which was actually in operation, a 2.824% improvement in propulsion efficiency was confirmed in comparison to the case of a base engine. This improvement in propulsion efficiency resulted in about 6.06% reduction in the specific fuel oil consumption and specific CO 2 emissions of the main engine during actual operation. - Highlights: • WHRS was theoretically applied to exhaust gas of a main engine for ship propulsion. • A dual loop EG-WHRS using water and R1234yf as working fluids has been suggested. • Limitation of single loop trilateral cycle was improved by the dual loop system. • The propulsion efficiency of 2.824% was improved by the dual loop EG-WHRS. • This resulted in about 6.06% reduction in the SFOC and specific CO

Integrated Main Propulsion System Performance Reconstruction Process/Models

Science.gov (United States)

Lopez, Eduardo; Elliott, Katie; Snell, Steven; Evans, Michael

2013-01-01

The Integrated Main Propulsion System (MPS) Performance Reconstruction process provides the MPS post-flight data files needed for postflight reporting to the project integration management and key customers to verify flight performance. This process/model was used as the baseline for the currently ongoing Space Launch System (SLS) work. The process utilizes several methodologies, including multiple software programs, to model integrated propulsion system performance through space shuttle ascent. It is used to evaluate integrated propulsion systems, including propellant tanks, feed systems, rocket engine, and pressurization systems performance throughout ascent based on flight pressure and temperature data. The latest revision incorporates new methods based on main engine power balance model updates to model higher mixture ratio operation at lower engine power levels.

A Review on the Faults of Electric Machines Used in Electric Ships

OpenAIRE

Dionysios V. Spyropoulos; Epaminondas D. Mitronikas

2013-01-01

Electric propulsion systems are today widely applied in modern ships, including transport ships and warships. The ship of the future will be fully electric, and not only its propulsion system but also all the other services will depend on electric power. The robust and reliable operation of the ship’s power system is essential. In this work, a review on the mechanical and electrical faults of electric machines that are used in electric ships is presented.

World Ships: The Solar-Photon Sail Option

Science.gov (United States)

Matloff, G. L.

The World Ship, a spacecraft large enough to simulate a small-scale terrestrial internal environment, may be the best feasible option to transfer members of a technological civilization between neighboring stars. Because of the projected size of these spacecraft, journey durations of ~1,000 years seem likely. One of the propulsion options for World Ships is the hyper-thin, likely space-manufactured solar-photon sail, unfurled as close to the migrating civilization's home star as possible. Because the sail and associated structure can be wound around the habitat while not in use, it represents the only known ultimately feasible interstellar propulsion system that can be applied for en route galactic-cosmic ray shielding as well as acceleration/ deceleration. This paper reviews the three suggested sail configurations that can be applied to world ship propulsion: parachute, hollow-body and hoop sails. Possible existing and advanced sail and structure materials and the predicted effects on the sail of the near-Sun space environment are reviewed. Consideration of solar-photon-sail World Ships also affects SETI (the Search for Extraterrestrial Intelligence). Can we detect such craft in flight? When in a star's lifetime is migration using such craft likely? What classes of stars are good candidates for solar-sail World-Ship searches?

Japan nuclear ship sea trial

International Nuclear Information System (INIS)

Yamazaki, Hiroshi; Kitamura, Toshikatus; Mizushima, Toshihiko

1992-01-01

The sea trial of the first Japan nuclear Ship 'MUTSU' was conducted from the end of October to December in 1990. The purpose of the sea trial was to verify the nuclear propulsive performances and maneuverabilities. The present report describes the results of the sea trial. These results are classified into four items: 1. Speed test and engineering performance tests 2. Maneuvering performance tests 3. Vibration tests 4. Other tests. Acceptable performances were demonstrated, as expected in the original design. The experience of the use of the Global Positioning System (GPS), which were newly adopted for the sea trial, is also reported. (author)

Nuclear ship accidents

International Nuclear Information System (INIS)

Oelgaard, P.L.

1993-05-01

In this report available information on 28 nuclear ship accident and incidents is considered. Of these 5 deals with U.S. ships and 23 with USSR ships. The ships are in almost all cases nuclear submarines. Only events that involve the nuclear propulsion plants, radiation exposures, fires/explosions and sea water leaks into the submarines are considered. Comments are made on each of the events, and at the end of the report an attempt is made to point out the weaknesses of the submarine designs which have resulted in the accidents. It is emphasized that much of the available information is of a rather dubious nature. consequently some of the assessments made may not be correct. (au)

Feasibility Study on Nuclear Propulsion Ship according to Economic Evaluation

Energy Technology Data Exchange (ETDEWEB)

Gil, Youngmi; Yoo, Seongjin; Oh, June; Byun, Yoonchul; Woo, Ilguk [Daewoo Shipbuilding and Marine Engineering Co., Ltd, Seoul (Korea, Republic of); Kim, Jiho; Choi, Suhn [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-05-15

The use of nuclear ships has been extending to the icebreaker, the deep-water exploration ship, and the floating nuclear power plant. Prior to developing the new ship, the relevant regulations need to be considered. In this study, we reviewed the nuclear ship-related regulations. In addition, economic value is one of the most important factors which should be considered in the pre-design phase. To evaluate the economics of the nuclear ship, we calculated Capital Expenditure (abbreviated as CAPEX) and Operation Expenditure (abbreviated as OPEX) for various types of ships. We reviewed the nuclear ship-related regulations and evaluated the economics of the nuclear ship compared to the diesel ship. The calculation result shows that economic feasibility of the nuclear ship depends on the oil price as well as the cost of the nuclear reactor.

Friction correction for model ship resistance and propulsion tests in ice at NRC's OCRE-RC

Directory of Open Access Journals (Sweden)

Michael Lau

2018-05-01

Full Text Available This paper documents the result of a preliminary analysis on the influence of hull-ice friction coefficient on model resistance and power predictions and their correlation to full-scale measurements. The study is based on previous model-scale/full-scale correlations performed on the National Research Council - Ocean, Coastal, and River Engineering Research Center's (NRC/OCRE-RC model test data. There are two objectives for the current study: (1 to validate NRC/OCRE-RC's modeling standards in regarding to its practice of specifying a CFC (Correlation Friction Coefficient of 0.05 for all its ship models; and (2 to develop a correction methodology for its resistance and propulsion predictions when the model is prepared with an ice friction coefficient slightly deviated from the CFC of 0.05. The mean CFC of 0.056 and 0.050 for perfect correlation as computed from the resistance and power analysis, respectively, have justified NRC/OCRE-RC's selection of 0.05 for the CFC of all its models. Furthermore, a procedure for minor friction corrections is developed. Keywords: Model test, Ice resistance, Power, Friction correction, Correlation friction coefficient

Mirror fusion propulsion system - A performance comparison with alternate propulsion systems for the manned Mars mission

International Nuclear Information System (INIS)

Deveny, M.; Carpenter, S.; O'connell, T.; Schulze, N.

1993-06-01

The performance characteristics of several propulsion technologies applied to piloted Mars missions are compared. The characteristics that are compared are Initial Mass in Low Earth Orbit (IMLEO), mission flexibility, and flight times. The propulsion systems being compared are both demonstrated and envisioned: Chemical (or Cryogenic), Nuclear Thermal Rocket (NTR) solid core, NTR gas core, Nuclear Electric Propulsion (NEP), and a mirror fusion space propulsion system. The proposed magnetic mirror fusion reactor, known as the Mirror Fusion Propulsion System (MFPS), is described. The description is an overview of a design study that was conducted to convert a mirror reactor experiment at Lawrence Livermore National Lab (LLNL) into a viable space propulsion system. Design principles geared towards minimizing mass and maximizing power available for thrust are identified and applied to the LLNL reactor design, resulting in the MFPS. The MFPS' design evolution, reactor and fuel choices, and system configuration are described. Results of the performance comparison shows that the MFPS minimizes flight time to 60 to 90 days for flights to Mars while allowing continuous return-home capability while at Mars. Total MFPS IMLEO including propellant and payloads is kept to about 1,000 metric tons. 50 refs

LCA-ship. Design tool for energy efficient ships. A Life Cycle Analysis Program for Ships. Final report

Energy Technology Data Exchange (ETDEWEB)

Jiven, Karl; Sjoebris, Anders [MariTerm AB, Goeteborg (Sweden); Nilsson, Maria [Lund Univ. (Sweden). Stiftelsen TEM; Ellis, Joanne; Traegaardh, Peter; Nordstroem, Malin [SSPA Sweden AB, Goeteborg (Sweden)

2004-05-01

In order to make it easier to include aspects during ship design that will improve environmental performance, general methods for life cycle calculations and a prototype tool for LCA calculations of ships and marine transportation have been developed. The base of the life cycle analyses is a comprehensive set of life cycle data that was collected for the materials and consumables used in ship construction and vessel operations. The computer tool developed makes it possible to quickly and simply specify (and calculate) the use of consumables over the vessel's life time cycle. Special effort has been made to allow the tool to be used for different types of vessels and sea transport. The main result from the project is the computer tool LCA ship, which incorporates collected and developed life cycle data for some of the most important materials and consumables used in ships and their operation. The computer application also contains a module for propulsion power calculations and a module for defining and optimising the energy system onboard the vessel. The tool itself is described in more detail in the Computer application manual. The input to the application should, as much as possible, be the kind of information that is normally found in a shipping company concerning vessel data and vessel movements. It all starts with defining the ship to be analysed and continues with defining how the ship is used over the lifetime. The tool contains compiled and processed background information about specific materials and processes (LCA data) connected to shipping operations. The LCA data is included in the tool in a processed form. LCA data for steel will for example include the environmental load from the steel production, the process to build the steel structure of the ship, the scrapping and the recycling phase. To be able to calculate the environmental load from the use of steel the total amount of steel used over the life cycle of the ship is also needed. The

Performance Criteria of Nuclear Space Propulsion Systems

Science.gov (United States)

Shepherd, L. R.

Future exploration of the solar system on a major scale will require propulsion systems capable of performance far greater than is achievable with the present generation of rocket engines using chemical propellants. Viable missions going deeper into interstellar space will be even more demanding. Propulsion systems based on nuclear energy sources, fission or (eventually) fusion offer the best prospect for meeting the requirements. The most obvious gain coming from the application of nuclear reactions is the possibility, at least in principle, of obtaining specific impulses a thousandfold greater than can be achieved in chemically energised rockets. However, practical considerations preclude the possibility of exploiting the full potential of nuclear energy sources in any engines conceivable in terms of presently known technology. Achievable propulsive power is a particularly limiting factor, since this determines the acceleration that may be obtained. Conventional chemical rocket engines have specific propulsive powers (power per unit engine mass) in the order of gigawatts per tonne. One cannot envisage the possibility of approaching such a level of performance by orders of magnitude in presently conceivable nuclear propulsive systems. The time taken, under power, to reach a given terminal velocity is proportional to the square of the engine's exhaust velocity and the inverse of its specific power. An assessment of various nuclear propulsion concepts suggests that, even with the most optimistic assumptions, it could take many hundreds of years to attain the velocities necessary to reach the nearest stars. Exploration within a range of the order of a thousand AU, however, would appear to offer viable prospects, even with the low levels of specific power of presently conceivable nuclear engines.

Accidents in nuclear ships

Energy Technology Data Exchange (ETDEWEB)

Oelgaard, P L [Risoe National Lab., Roskilde (Denmark); [Technical Univ. of Denmark, Lyngby (Denmark)

1996-12-01

This report starts with a discussion of the types of nuclear vessels accidents, in particular accidents which involve the nuclear propulsion systems. Next available information on 61 reported nuclear ship events in considered. Of these 6 deals with U.S. ships, 54 with USSR ships and 1 with a French ship. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/explosions, sea-water leaks into the submarines and sinking of vessels are considered. For each event a summary of available information is presented, and comments are added. In some cases the available information is not credible, and these events are neglected. This reduces the number of events to 5 U.S. events, 35 USSR/Russian events and 1 French event. A comparison is made between the reported Soviet accidents and information available on dumped and damaged Soviet naval reactors. It seems possible to obtain good correlation between the two types of events. An analysis is made of the accident and estimates are made of the accident probabilities which are found to be of the order of 10{sup -3} per ship reactor years. It if finally pointed out that the consequences of nuclear ship accidents are fairly local and does in no way not approach the magnitude of the Chernobyl accident. It is emphasized that some of the information on which this report is based, may not be correct. Consequently some of the results of the assessments made may not be correct. (au).

Accidents in nuclear ships

International Nuclear Information System (INIS)

Oelgaard, P.L.

1996-12-01

This report starts with a discussion of the types of nuclear vessels accidents, in particular accidents which involve the nuclear propulsion systems. Next available information on 61 reported nuclear ship events in considered. Of these 6 deals with U.S. ships, 54 with USSR ships and 1 with a French ship. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/explosions, sea-water leaks into the submarines and sinking of vessels are considered. For each event a summary of available information is presented, and comments are added. In some cases the available information is not credible, and these events are neglected. This reduces the number of events to 5 U.S. events, 35 USSR/Russian events and 1 French event. A comparison is made between the reported Soviet accidents and information available on dumped and damaged Soviet naval reactors. It seems possible to obtain good correlation between the two types of events. An analysis is made of the accident and estimates are made of the accident probabilities which are found to be of the order of 10 -3 per ship reactor years. It if finally pointed out that the consequences of nuclear ship accidents are fairly local and does in no way not approach the magnitude of the Chernobyl accident. It is emphasized that some of the information on which this report is based, may not be correct. Consequently some of the results of the assessments made may not be correct. (au)

Fast ship

OpenAIRE

Keuning, J.A.

2014-01-01

The invention concerns a ship whereby the hull and the mechanical propulsion device are designed such that the Froude number is larger than 0.5. In the aft ship the hull has a bottom with V-shaped bottom surfaces with a deadrise angle that is less than 40 degrees and the hull has substantially vertical sides. In the hull are a passenger compartment and a trim tank. The trim tank volume is such that the weight of a filled trim tank is more than 30 % of the weight of displacement of the hull wi...

Evaluation of the Service Performance of Ships

DEFF Research Database (Denmark)

Andersen, Poul; Borrod, Anne-Sophie; Blanchot, Hervé

2005-01-01

A simple method has been established for the evaluation of the service performance of ships. Input data are easily collected daily on board and transformed to a well-defined condition that makes possible the comparison between ships, for instance, sister ships, and between different time periods...... of voyages for the same ship. The procedure has been applied to two ships that are identical, with the exception that one has a conventional propeller, whereas the other one is fitted with a high-efficiency propeller of the KAPPEL type. The results are obtained from a period of 2 years steaming for both...

Nuclear powered ships. Findings from a feasibility study

International Nuclear Information System (INIS)

Namikawa, Shunichiro; Maerli, Morten Bremer; Hoffmann, Peter Nyegaard; Brodin, Erik

2011-01-01

Nuclear shipping is attractive for several reasons, one of which is its positive effect on emissions (CO 2 , NOx and SOx). The benefits, however, do not come without risks of possible harmful effects on humans and wildlife. Nuclear ships set themselves apart from conventional ships, as well as from on-shore nuclear power-plants, on several counts. 1) The reactor-unit are non-stationary, and the reactor is subject to the ship motions. 2) Ship reactors must be compact due to space constraints. 3) Special design considerations are required to ensure reactor safety and security, as well as to enable refuelling. 4) A naval nuclear fuel cycle infrastructure for fuel fabrication, handling, and disposal is needed. Technological feasibility of nuclear shipping is by itself inconclusive to a expansion into civilian applications and use. Civilian nuclear propulsion needs to be commercially viable and politically acceptable. Appropriate legislation must be in place, and nuclear shipping concepts with proven safety records and highest possible nuclear proliferation-resistance must be established. Possible 'showstoppers' to a viable nuclear civilian shipping industry are outlined in the paper in view of Political, Technical, Regulatory, Commercial, Safety and Security aspects. Further, different types of ships with different propulsion system are compared in lights of life cycle cost and air emission. (author)

High-performance-vehicle technology. [fighter aircraft propulsion

Science.gov (United States)

Povinelli, L. A.

1979-01-01

Propulsion needs of high performance military aircraft are discussed. Inlet performance, nozzle performance and cooling, and afterburner performance are covered. It is concluded that nonaxisymmetric nozzles provide cleaner external lines and enhanced maneuverability, but the internal flows are more complex. Swirl afterburners show promise for enhanced performance in the high altitude, low Mach number region.

Information report presented in application of article 145 of the regulation by the commission of national defense and armed forces about the propulsion system of the second aircraft carrier; Rapport d'information depose en application de l'article 145 du reglement par la commission de la defense nationale et des forces armees sur le mode de propulsion du second porte-avions

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-11-01

In the framework of the project of launching of a sister-ship to the Charles de Gaulle aircraft carrier, this report makes an objective analysis of the different possible propulsion systems that can be considered for this battle ship according to different criteria: 1 - two possible energy sources and four possible configurations of aircraft carrier considered: alternative between nuclear propulsion and conventional propulsion, the two nuclear ships eventualities, the hypothesis of an entirely French-made classical propulsion ship, the opportunity of a French-British cooperation for a conventional aircraft carrier project; 2 - decision criteria: operational need, cost, industrial and technological stakes, constraints linked with daily ship and crew life; 3 - propulsion systems alternative: conventional propulsion and reinforcement of the European defense policy, nuclear propulsion for an operational superiority and for a complementarity with the Charles de Gaulle. (J.S.)

Multipole superconducting electric motors for ship propulsion

International Nuclear Information System (INIS)

Thullen, P.; Keim, T.A.; Minervini, J.V.

1975-01-01

While a great deal of attention has been paid to two-pole superconducting synchronous machines, very little analysis of low speed, multipole superconducting synchronous machines has been done. Such machines may prove desirable as drive motors in ship drive systems. Results are presented of an analysis which assumes a motor of sufficient size that the airgap may be considered to be flat. A power output expression is given which shows the effects of machine geometry and superconductor characteristics on machine size. Based on this expression, a 40,000 hp 120 rpm motor is sized, and the resulting machine is compared with a conventional ship drive motor. The comparison illustrates possible size reductions through the application of superconductivity

Defining the Ecological Coefficient of Performance for an Aircraft Propulsion System

Science.gov (United States)

Şöhret, Yasin

2018-05-01

The aircraft industry, along with other industries, is considered responsible these days regarding environmental issues. Therefore, the performance evaluation of aircraft propulsion systems should be conducted with respect to environmental and ecological considerations. The current paper aims to present the ecological coefficient of performance calculation methodology for aircraft propulsion systems. The ecological coefficient performance is a widely-preferred performance indicator of numerous energy conversion systems. On the basis of thermodynamic laws, the methodology used to determine the ecological coefficient of performance for an aircraft propulsion system is parametrically explained and illustrated in this paper for the first time. For a better understanding, to begin with, the exergy analysis of a turbojet engine is described in detail. Following this, the outputs of the analysis are employed to define the ecological coefficient of performance for a turbojet engine. At the end of the study, the ecological coefficient of performance is evaluated parametrically and discussed depending on selected engine design parameters and performance measures. The author asserts the ecological coefficient of performance to be a beneficial indicator for researchers interested in aircraft propulsion system design and related topics.

Assembly and Alignment of Ship Power Plants in Modern Shipbuilding

OpenAIRE

A. O. Mikhailov; K. N. Morozov

2013-01-01

Fine alignment of main ship power plants mechanisms and shaft lines provides long-term and failure-free performance of propulsion system while fast and high-quality installation of mechanisms and shaft lines decreases common labor intensity. For checking shaft line allowed stress and setting its alignment it is required to perform calculations considering various stages of life cycle. In 2012 JSC SSTC developed special software complex “Shaftline” for calculation of align...

Performance enhancement using power beaming for electric propulsion earth orbital transporters

International Nuclear Information System (INIS)

Dagle, J.E.

1991-01-01

An electric propulsion Earth orbital transport vehicle (EOTV) can effectively deliver large payloads using much less propellant than chemical transfer methods. By using an EOTV instead of a chemical upper stage, either a smaller launch vehicle can be used for the same satellite mass or a larger satellite can be deployed using the same launch vehicle. However, the propellant mass savings from using the higher specific impulse of electric propulsion may not be enough to overcome the disadvantage of the added mass and cost of the electric propulsion power source. Power system limitations have been a major factor delaying the acceptance and use of electric propulsion. This paper outlines the power requirements of electric propulsion technology being developed today, including arcjets, magnetoplasmadynamic (MPD) thrusters, and ion engines. Power supply characteristics are discussed for nuclear, solar, and power-beaming systems. Operational characteristics are given for each, as are the impacts of the power supply alternative on the overall craft performance. Because of its modular nature, the power-beaming approach is able to meet the power requirements of all three electric propulsion types. Also, commonality of approach allows different electric propulsion approaches to be powered by a single power supply approach. Power beaming exhibits better flexibility and performance than on-board nuclear or solar power systems

Performance evaluation of 1 kw PEFC

Energy Technology Data Exchange (ETDEWEB)

Komaki, Hideaki [Ishikawajima-Harima Heavy Industries Co., Ltd. Tokyo (Japan); Tsuchiyama, Syozo [Shipbuilding Research Association, Minato-ky, Tokyo (Japan)

1996-12-31

This report covers part of a joint study on a PEFC propulsion system for surface ships, summarized in a presentation to this Seminar, entitled {open_quote}Study on a PEFC Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The aspect treated here concerns the effects brought on PEFC operating performance by conditions particular to shipboard operation. The performance characteristics were examined through tests performed on a 1 kw stack and on a single cell (Manufactured by Fuji Electric Co., Ltd.). The tests covered the items (1) to (4) cited in the headings of the sections that follow. Specifications of the stack and single cell are as given.

Features of Load and Wear of Main Propulsion Devices on Sea-Going Ships with Piston Combustion Engines and Their Impact on Changes in Technical States of the Systems

Directory of Open Access Journals (Sweden)

Girtler Jerzy

2017-12-01

Full Text Available The paper presents the specificity of operation of propulsion systems of seagoing ships which causes the need to control the load on them, especially on their engines called main engines. The characteristics of the load on the propulsion systems, especially on the main engines as well as on the shaft lines and propellers driven by the engines, along with the process of wear in tribological joints (sliding tribological systems of the machines have been described herein. Using examples of typical types of wear (both linear and volumetric for the tribological systems of this sort, interpretation of states of their wear has been provided with regards to the wear levels defined as acceptable, unacceptable and catastrophic. The following hypotheses have been formulated: 1 hypothesis explaining necessity to consider the loads on the systems under operation as stochastic processes; 2 hypothesis explaining a possibility of considering the processes as stationary; and 3 hypothesis explaining why it can be assumed that a given technical state of any tribological system can be considered as dependent only on the directly preceding state and stochastically independent of the states that existed earlier. Accepting the hypotheses as true, a four-state continuous-time semi-Markov process has been proposed in the form of a model of changes in condition of a propulsion system (PS of any ship. The model includes the most significant states affecting safety of a ship at sea, such as: s0 - PS ability state, s1 - PS disability state due to damage to the main engine (ME, s2 - PS disability state due to damage to the shaft line (SL and s3 - PS disability state due to damage to the propeller (P. Probability of occurrence (changes of the states has also been demonstrated.

Utilization of uranium cost/benefit study for nuclear powered merchant ships. Special study

International Nuclear Information System (INIS)

Smith, E.R.

1977-05-01

This study presents a cost/benefit analysis for the utilization of uranium in merchant ships versus the use of uranium for the generation of electricity in central power stations. The study concludes that an alternative naval fuel to oil must be developed for the merchant marine to reduce U.S. dependency upon foreign supplies of a critical fuel. The study further indicates that use of uranium for ship propulsion results in transport of large quantities of needed import/exports while the residual oil saved will generate the same quantity of electricity in a central power station as the uranium used for ship propulsion

Towards a nuclear merchant ship

International Nuclear Information System (INIS)

Nicholson, R.L.R.; Llewelyn, G.I.W.; Farmer, A.A.

1976-01-01

The operation of nuclear merchant ships is likely to be attended by a number of constraints and requirements. Not all of these can be fully resolved until such ships come into use and the necessary experience and confidence have been acquired. But the timing of commercial introduction, if it comes about, will depend on the relative economics of nuclear versus fossil fuel propulsion, and the differences in turn depend in part on the operating costs particular to nuclear ships. A review of operation aspects is essential not only to commercial appraisal; each country whose trade may be carried in nuclear ships - whether it will build such ships or not - will have occasion to give some attention to the problems. It is an international problem and is, as noted later, being considered internationally. This paper; i) reviews some of the operational aspects as seen in the U.K.; ii) summarizes views received by the Nuclear Merchant Ship Unit (NMSU) from U.K. shipping, shipbuilding and nuclear industries on the prospects of a U.K. nuclear merchant ship. (author)

Race-track coils for a 3 MW HTS ship motor

Energy Technology Data Exchange (ETDEWEB)

Ueno, E., E-mail: ueno-eisaku@sei.co.jp; Kato, T.; Hayashi, K.

2014-09-15

Highlights: • Sumitomo Electric manufactured the HTS field coils for a 3 MW HTS ship motor. • The motor was developed and successfully passed the loading test by Kawasaki Heavy. • We tested and obtained the basic data to evaluate the 20-year durability of coils. - Abstract: Since the discovery of high-temperature superconductivity (HTS), Sumitomo Electric has been developing silver-sheathed Bi2223 superconducting wire and products. Ship propulsion motors are one of the most promising applications of HTS. Sumitomo Electric Industries, Ltd. (SEI) has recently manufactured 24 large racetrack coils, using 70 km long DI-BSCCO wires, for use in a 3 MW HTS motor developed by Kawasaki Heavy Industries, Ltd. (KHI). The 3 MW HTS motor, using our newly developed racetrack coils, has successfully passed the loading test. It is particularly important that the HTS field coils used in ship propulsion motors can withstand the expansive forces repeatedly applied to them. As racetrack type coils have straight sections, the support mechanism they require to withstand expansive forces is very different from that of circular coils. Therefore, we ran tests and obtained the basic data to evaluate the 20-year durability of racetrack coils against the repeatedly applied expansive forces expected in domestic ship propulsion motors.

Potential of biofuels for shipping. Final Report

Energy Technology Data Exchange (ETDEWEB)

Florentinus, A.; Hamelinck, C.; Van den Bos, A.; Winkel, R.; Cuijpers, M. [Ecofys Netherlands, Utrecht (Netherlands)

2012-01-15

Biofuels could be one of the options to realize a lower carbon intensity in the propulsion of ships and also possibly reduce the effect of ship emissions on local air quality. Therefore, EMSA, the European Maritime Safety Agency, is evaluating if and how biofuels could be used in the shipping sector as an alternative fuel. To determine the potential of biofuels for ships, a clearer picture is needed on technical and organizational limitations of biofuels in ships, both on board of the ship as in the fuel supply chain to the ship. Economic and sustainability analysis of biofuels should be included in this picture, as well as an overview on current and potential policy measures to stimulate the use of biofuels in shipping. Ecofys has determined the potential of biofuels, based on analysis of collected data through literature review, own expertise and experiences, direct communication with EMSA, research publications, market developments based on press and other media, and consultations with relevant stakeholders in the shipping market.

METHODOLOGY OF THE HYBRID PROPULSION SYSTEM (DMP & DEP FOR TRIMARAN TYPE FAST PATROL BOAT

Directory of Open Access Journals (Sweden)

Aulia Widyandari

2012-04-01

Full Text Available There are lot of research done to develop a patrol boat, from the modification of hull model until propulsion system equipment. For example the model ship type AMV (Advanced Marine Vehicle was developed starting from the Catamaran, Trimaran and  Pentamaran model. Everything is aimed at obtaining the ship design that has the speed and stability. In addition to achieving high-speed vessel must be equipped with propulsion (Main Power is great, that means the main engine dimensions, auxiliary equipments and fuel tanks is too large. Many Limitations of space on the ship's engine room trimaran vessel is the main obstacle in designing propulsion system. Beside that Patrol boat should have many missions speed, so propulsion system should be designed at that conditions.   Hybrid propulsion is a combination of Diesel Mechanical Propulsion (DMP with Diesel Electric Propulsion (DEP. DMP system is connected directly to the propeller shaft (or through a reduction-gear. DMP has provide more efficiency rate of 95%. While DEP is only able to provide efficiency by 85% - 89% is slightly lower than DMP, but the DEP offers many advantages such as simplicity and suitability in the rotational speed settings, control systems, engine power production Redundancy, Flexibility in the design of equipments layout in engine rooms, noise, vibration and fuel consumption efficiency which affects the lower pollution.   Design of Hybrid Propulsion system can be satisfied and achieved the Power requirements and optimally at all speed condition of patrol boat. Therefore the author made using modeling Maxsurf-11.12 software and carried out various optimization of the choice of main engine, propeller and system conditions for fast patrol boat cruise. 

Analysis of ship maneuvering data from simulators

Science.gov (United States)

Frette, V.; Kleppe, G.; Christensen, K.

2011-03-01

We analyze complex manuevering histories of ships obtained from training sessions on bridge simulators. Advanced ships are used in fields like offshore oil exploration: dive support vessels, supply vessels, anchor handling vessels, tugs, cable layers, and multi-purpose vessels. Due to high demands from the operations carried out, these ships need to have very high maneuverability. This is achieved through a propulsion system with several thrusters, water jets, and rudders in addition to standard propellers. For some operations, like subsea maintenance, it is crucial that the ship accurately keeps a fixed position. Therefore, bridge systems usually incorporate equipment for Dynamic Positioning (DP). DP is a method to keep ships and semi submersible rigs in a fixed position using the propulsion systems instead of anchors. It may also be used for sailing a vessel from one position to another along a predefined route. Like an autopilot on an airplane, DP may operate without human involvement. The method relies on accurate determination of position from external reference systems like GPS, as well as a continuously adjusted mathematical model of the ship and external forces from wind, waves and currents. In a specific simulator exercise for offshore crews, a ship is to be taken up to an installation consisting of three nearby oil platforms connected by bridges (Frigg field, North Sea), where a subsea inspection is to be carried out. Due to the many degrees of freedom during maneuvering, including partly or full use of DP, the chosen routes vary significantly. In this poster we report preliminary results on representations of the complex maneuvering histories; representations that allow comparison between crew groups, and, possibly, sorting of the different strategic choices behind.

Development of helium transfer coupling of 1 MW-class HTS motor for podded ship propulsion system

Energy Technology Data Exchange (ETDEWEB)

Kosuge, Eiji; Gocho, Yoshitsugu; Okumura, Kagao; Yamaguchi, Mitsugi [JapaneseSuperconductivity Organization, 135-8533, Tokyo (Japan); Umemoto, Katsuya; Aizawa, Kiyoshi; Yokoyama, Minoru; Takao, Satoru, E-mail: gocho@jso--new-scm.co.j [Kawasaki Heavy Industries LTD., 673-8666, Hyogo (Japan)

2010-06-01

Research and development of 1 MW superconducting motor are being made aiming at the efficiency improvement for the podded type ship propulsion. The basic machine configuration is similar to steam turbine generators, having a rotating horizontal shaft. As for the motor composed of rotating superconducting field, one of the most critical issues is to provide a technically viable helium transfer coupling (HTC). The field winding of 1 MW motor is cooled with cryogenic helium gas. The HTC needs to supply the cryogenic helium gas with an appropriate flow rate from the stationary part to the rotating field winding region through a hollowed shaft in order not to lose superconducting state of the winding. A full size prototype of HTC was developed prior to the actual one to demonstrate its technical acceptability. The fundamental data with regard to the supply of the refrigerated helium gas were successfully obtained at the rated speed. This work has been supported by New Energy, and Industrial Technology Development Organization (NEDO).

Biomimetic propulsion under random heaving conditions, using active pitch control

Science.gov (United States)

Politis, Gerasimos; Politis, Konstantinos

2014-05-01

Marine mammals travel long distances by utilizing and transforming wave energy to thrust through proper control of their caudal fin. On the other hand, manmade ships traveling in a wavy sea store large amounts of wave energy in the form of kinetic energy for heaving, pitching, rolling and other ship motions. A natural way to extract this energy and transform it to useful propulsive thrust is by using a biomimetic wing. The aim of this paper is to show how an actively pitched biomimetic wing could achieve this goal when it performs a random heaving motion. More specifically, we consider a biomimetic wing traveling with a given translational velocity in an infinitely extended fluid and performing a random heaving motion with a given energy spectrum which corresponds to a given sea state. A formula is invented by which the instantaneous pitch angle of the wing is determined using the heaving data of the current and past time steps. Simulations are then performed for a biomimetic wing at different heave energy spectra, using an indirect Source-Doublet 3-D-BEM, together with a time stepping algorithm capable to track the random motion of the wing. A nonlinear pressure type Kutta condition is applied at the trailing edge of the wing. With a mollifier-based filtering technique, the 3-D unsteady rollup pattern created by the random motion of the wing is calculated without any simplifying assumptions regarding its geometry. Calculated unsteady forces, moments and useful power, show that the proposed active pitch control always results in thrust producing motions, with significant propulsive power production and considerable beneficial stabilizing action to ship motions. Calculation of the power required to set the pitch angle prove it to be a very small percentage of the useful power and thus making the practical application of the device very tractable.

Effect of stern hull shape on turning circle of ships

Science.gov (United States)

Jaswar, Maimun, A.; Wahid, M. A.; Priyanto, A.; Zamani, Pauzi, Saman

2012-06-01

Many factors such as: stern hull shape, length, draught, trim, propulsion system and external forces affecting the drift angle influence rate of turn and size of turning circle of ships. This paper discusses turning circle characteristics of U and V stern hull shape of Very Large Crude Oil Carrier (VLCC) ships. The ships have same principal dimension such as length, beam, and draught. The turning circle characteristics of the VLCC ships are simulated at 35 degree of rudder angle. In the analysis, firstly, turning circle performance of U-type VLCC ship is simulated. In the simulation, initial ship speed is determined using given power and rpm. Hydrodynamic derivatives coefficients are determined by including effect of fullness of aft run. Using the obtained, speed and hydrodynamic coefficients, force and moment acting on hull, force and moment induced by propeller, force and moment induced by rudder are determined. Finally, ship trajectory, ratio of speed, yaw angle and drift angle are determined. Results of simulation results of the VLCC ship are compared with the experimental one as validation. Using the same method, V-type VLCC is simulated and the simulation results are compared with U-type VLCC ship. Results shows the turning circle of U-type is larger than V-type due to effect stern hul results of simulation are.

Nuclear ship accidents, description and analysis

International Nuclear Information System (INIS)

Oelgaard, P.L.

1993-03-01

In this report available information on 44 reported nuclear ship events is considered. Of these 6 deals with U.S. ships and 38 with USSR ships. The ships are in almost all cases nuclear submarines. Only events that involve the sinking of vessels, the nuclear propulsion plants, radiation exposures, fires/ explosions, sea-water leaks into the submarines and sinking of vessels are considered. Comments are made on each of the events, and at the end of the report an attempt is made to point out the weaknesses of the submarine designs which have resulted in the accidents. It is emphasized that some of the information of which this report is based, may be of dubious nature. Consequently some of the results of the assessments made may not be correct. (au)

Mars Hybrid Propulsion System Trajectory Analysis. Part I; Crew Missions

Science.gov (United States)

Chai, Patrick R.; Merrill, Raymond G.; Qu, Min

2015-01-01

NASAs Human spaceflight Architecture team is developing a reusable hybrid transportation architecture in which both chemical and electric propulsion systems are used to send crew and cargo to Mars destinations such as Phobos, Deimos, the surface of Mars, and other orbits around Mars. By combining chemical and electrical propulsion into a single space- ship and applying each where it is more effective, the hybrid architecture enables a series of Mars trajectories that are more fuel-efficient than an all chemical architecture without significant increases in flight times. This paper provides the analysis of the interplanetary segments of the three Evolvable Mars Campaign crew missions to Mars using the hybrid transportation architecture. The trajectory analysis provides departure and arrival dates and propellant needs for the three crew missions that are used by the campaign analysis team for campaign build-up and logistics aggregation analysis. Sensitivity analyses were performed to investigate the impact of mass growth, departure window, and propulsion system performance on the hybrid transportation architecture. The results and system analysis from this paper contribute to analyses of the other human spaceflight architecture team tasks and feed into the definition of the Evolvable Mars Campaign.

A Ship Propulsion System Model for Fault-tolerant Control

DEFF Research Database (Denmark)

Izadi-Zamanabadi, Roozbeh; Blanke, M.

This report presents a propulsion system model for a low speed marine vehicle, which can be used as a test benchmark for Fault-Tolerant Control purposes. The benchmark serves the purpose of offering realistic and challenging problems relevant in both FDI and (autonomous) supervisory control area...

Proceedings of ICETECH 2008 : the 8. international conference and exhibition on performance of ships and structures in ice. 2. ed.

Energy Technology Data Exchange (ETDEWEB)

Bercha, F. (ed.) [Bercha Group, Calgary, AB (Canada); Bercha, S. (comp.) [Bercha Group, Calgary, AB (Canada); Pilkington, R. [CANATEC Associates International Ltd., Calgary, AB (Canada)

2008-09-15

The rapid growth and renewed interest in oil and gas exploration and production in Arctic offshore regions has resulted in an increase in maritime transport through northern sea routes, including the Canadian Northwest Passage. This conference included both plenary and technical sessions which addressed issues facing offshore resource development in ice-covered areas, such as construction of offshore platforms; pipelines and facilities; and ice-structure interactions in terms of ice loads and ice mechanics. New offshore developments in ice-covered areas were discussed with reference to potential damage caused by dynamic ice loads, risk assessment, personnel safety, and emergency evacuation rescue. The global warming implications to the Arctic were also discussed along with Arctic geopolitics. The technical session on ships addressed ship performance in ice; propulsion systems; offshore operations; ice loads and hull strength; and icebreaker designs. Ice properties and observations were reviewed along with ice detection and mapping techniques. Developments in the Sakhalin Sea were reviewed along with codes, regulations and standards. Other technical sessions included ice scour and gouging; Arctic escape, evacuation and rescue (EER) operations; oil spill protection and response; and a special session on Arctic marine shipping assessment (AMSA). The conference featured 63 presentations, of which 24 have been catalogued separately for inclusion in this database. refs., tabs., figs.

Proceedings of ICETECH 2008 : the 8. international conference and exhibition on performance of ships and structures in ice. 2. ed.

International Nuclear Information System (INIS)

Bercha, F.; Bercha, S.; Pilkington, R.

2008-09-01

The rapid growth and renewed interest in oil and gas exploration and production in Arctic offshore regions has resulted in an increase in maritime transport through northern sea routes, including the Canadian Northwest Passage. This conference included both plenary and technical sessions which addressed issues facing offshore resource development in ice-covered areas, such as construction of offshore platforms; pipelines and facilities; and ice-structure interactions in terms of ice loads and ice mechanics. New offshore developments in ice-covered areas were discussed with reference to potential damage caused by dynamic ice loads, risk assessment, personnel safety, and emergency evacuation rescue. The global warming implications to the Arctic were also discussed along with Arctic geopolitics. The technical session on ships addressed ship performance in ice; propulsion systems; offshore operations; ice loads and hull strength; and icebreaker designs. Ice properties and observations were reviewed along with ice detection and mapping techniques. Developments in the Sakhalin Sea were reviewed along with codes, regulations and standards. Other technical sessions included ice scour and gouging; Arctic escape, evacuation and rescue (EER) operations; oil spill protection and response; and a special session on Arctic marine shipping assessment (AMSA). The conference featured 63 presentations, of which 24 have been catalogued separately for inclusion in this database. refs., tabs., figs

Optimization of the availability and safety relationship: case study of naval nuclear propulsion

International Nuclear Information System (INIS)

Guimaraes, Leonam dos Santos

2005-01-01

The relationship between energy generation availability and the safety of the nuclear installation which produces this energy assumes a very special characteristic when we are dealing with naval propulsion plants. This relationship has no parallel with commercial nuclear power plants. A ship at sea is in safety only if she could dispose quickly of the energy produced by your nuclear propulsion plant. If the nuclear steam production is not assured, specially due to safety reasons, the ship maneuverability, and so its own safety it is seriously affected. We could then perceive that safety of the nuclear installation is depends on safety of the ship, which depends by its side on the availability of nuclear power. This paper intends to present briefly the main aspects of this relation. (author)

Nuclear propulsion in high yield vessels

International Nuclear Information System (INIS)

Vergara Aimone, Julio

2000-01-01

Current developments in advanced ship design brings high-speed maritime transportation closer to reality, aiming to create new markets and to recover a fraction of the high value goods now shipped only by air. High-speed transport is growing at a rate of 15% per year, higher than air transport and at a fraction of air tariffs. Although such growth rate is restricted to passengers and automobiles, there is a potential for high-speed cargo in some routes. A recent proposal is Fast Ship, a 260 m long, 40 m wide concept designed to cruise from Philadelphia to Cherbourg in less that 4 days, for a door-to-door timely cargo delivery of 7 days, thanks to an advanced hull design, and a high power propulsion plant to compensate for weather-related delays. However, almost 40% of the total operation cost would be fuel. This appears to be a natural application for nuclear power, in a similar way to the golden age of this technology. A nuclear Fast Ship would save almost 5000 tons of a fuel per trip, and about half of such spare might be available for additional cargo. Furthermore, operation costs would be smaller and very stable to resource price fluctuation, plus a few other advantages. For other ocean markets, such as the Asia-America route, nuclear power would become a much better choice. This paper discusses the reactor type and layout suitable for such application. The ship designer is aware of the current proposal, although the power pack is not readily available today and its political aspects have not been dealt with. The economy of our nation relies on exports and almost 90% of such flow goes by sea. It is also possible that in the future, Mercosur might have a dependency on such high-speed transport mode and propulsion system (au)

Mean velocity and moments of turbulent velocity fluctuations in the wake of a model ship propulsor

Energy Technology Data Exchange (ETDEWEB)

Pego, J.P. [Universitaet Erlangen-Nuernberg, LSTM, Erlangen, Lehrstuhl fuer Stroemungsmechanik, Erlangen (Germany); Faculdade de Engenharia da Universidade do Porto, Porto (Portugal); Lienhart, H.; Durst, F. [Universitaet Erlangen-Nuernberg, LSTM, Erlangen, Lehrstuhl fuer Stroemungsmechanik, Erlangen (Germany)

2007-08-15

Pod drives are modern outboard ship propulsion systems with a motor encapsulated in a watertight pod, whose shaft is connected directly to one or two propellers. The whole unit hangs from the stern of the ship and rotates azimuthally, thus providing thrust and steering without the need of a rudder. Force/momentum and phase-resolved laser Doppler anemometry (LDA) measurements were performed for in line co-rotating and contra-rotating propellers pod drive models. The measurements permitted to characterize these ship propulsion systems in terms of their hydrodynamic characteristics. The torque delivered to the propellers and the thrust of the system were measured for different operation conditions of the propellers. These measurements lead to the hydrodynamic optimization of the ship propulsion system. The parameters under focus revealed the influence of distance between propeller planes, propeller frequency of rotation ratio and type of propellers (co- or contra-rotating) on the overall efficiency of the system. Two of the ship propulsion systems under consideration were chosen, based on their hydrodynamic characteristics, for a detailed study of the swirling wake flow by means of laser Doppler anemometry. A two-component laser Doppler system was employed for the velocity measurements. A light barrier mounted on the axle of the rear propeller motor supplied a TTL signal to mark the beginning of each period, thus providing angle information for the LDA measurements. Measurements were conducted for four axial positions in the slipstream of the pod drive models. The results show that the wake of contra-rotating propeller is more homogeneous than when they co-rotate. In agreement with the results of the force/momentum measurements and with hypotheses put forward in the literature (see e.g. Poehls in Entwurfsgrundlagen fuer Schraubenpropeller, 1984; Schneekluth in Hydromechanik zum Schiffsentwurf, 1988; Breslin and Andersen in Hydrodynamics of ship propellers, 1996

Mean velocity and moments of turbulent velocity fluctuations in the wake of a model ship propulsor

Science.gov (United States)

Pêgo, J. P.; Lienhart, H.; Durst, F.

2007-08-01

Pod drives are modern outboard ship propulsion systems with a motor encapsulated in a watertight pod, whose shaft is connected directly to one or two propellers. The whole unit hangs from the stern of the ship and rotates azimuthally, thus providing thrust and steering without the need of a rudder. Force/momentum and phase-resolved laser Doppler anemometry (LDA) measurements were performed for in line co-rotating and contra-rotating propellers pod drive models. The measurements permitted to characterize these ship propulsion systems in terms of their hydrodynamic characteristics. The torque delivered to the propellers and the thrust of the system were measured for different operation conditions of the propellers. These measurements lead to the hydrodynamic optimization of the ship propulsion system. The parameters under focus revealed the influence of distance between propeller planes, propeller frequency of rotation ratio and type of propellers (co- or contra-rotating) on the overall efficiency of the system. Two of the ship propulsion systems under consideration were chosen, based on their hydrodynamic characteristics, for a detailed study of the swirling wake flow by means of laser Doppler anemometry. A two-component laser Doppler system was employed for the velocity measurements. A light barrier mounted on the axle of the rear propeller motor supplied a TTL signal to mark the beginning of each period, thus providing angle information for the LDA measurements. Measurements were conducted for four axial positions in the slipstream of the pod drive models. The results show that the wake of contra-rotating propeller is more homogeneous than when they co-rotate. In agreement with the results of the force/momentum measurements and with hypotheses put forward in the literature (see e.g. Poehls in Entwurfsgrundlagen für Schraubenpropeller, 1984; Schneekluth in Hydromechanik zum Schiffsentwurf, 1988; Breslin and Andersen in Hydrodynamics of ship propellers, 1996

Nuclear rockets: High-performance propulsion for Mars

International Nuclear Information System (INIS)

Watson, C.W.

1994-05-01

A new impetus to manned Mars exploration was introduced by President Bush in his Space Exploration Initiative. This has led, in turn, to a renewed interest in high-thrust nuclear thermal rocket propulsion (NTP). The purpose of this report is to give a brief tutorial introduction to NTP and provide a basic understanding of some of the technical issues in the realization of an operational NTP engine. Fundamental physical principles are outlined from which a variety of qualitative advantages of NTP over chemical propulsion systems derive, and quantitative performance comparisons are presented for illustrative Mars missions. Key technologies are described for a representative solid-core heat-exchanger class of engine, based on the extensive development work in the Rover and NERVA nuclear rocket programs (1955 to 1973). The most driving technology, fuel development, is discussed in some detail for these systems. Essential highlights are presented for the 19 full-scale reactor and engine tests performed in these programs. On the basis of these tests, the practicality of graphite-based nuclear rocket engines was established. Finally, several higher-performance advanced concepts are discussed. These have received considerable attention, but have not, as yet, developed enough credibility to receive large-scale development

Numerical analysis of a waterjet propulsion system

NARCIS (Netherlands)

Bulten, N.W.H.

2006-01-01

A waterjet propulsion system is used to propel ships, using a pump which produces a high speed jet. A standard waterjet installation can be divided into an inlet, a pump and a nozzle. For manoeuvring and reversing purposes an additional steering device can be integrated into the installation. The

Experimental Methods for UAV Aerodynamic and Propulsion Performance Assessment

Directory of Open Access Journals (Sweden)

Stefan ANTON

2015-06-01

Full Text Available This paper presents an experimental method for assessing the performances and the propulsion power of a UAV in several points based on telemetry. The points in which we make the estimations are chosen based on several criteria and the fallowing parameters are measured: airspeed, time-to-climb, altitude and the horizontal distance. With the estimated propulsion power and knowing the shaft motor power, the propeller efficiency is determined at several speed values. The shaft motor power was measured in the lab using the propeller as a break. Many flights, using the same UAV configuration, were performed before extracting flight data, in order to reduce the instrumental or statistic errors. This paper highlights both the methodology of processing the data and the validation of theoretical results.

Magnetic levitation and MHD propulsion

Science.gov (United States)

Tixador, P.

1994-04-01

Magnetic levitation and MHD propulsion are now attracting attention in several countries. Different superconducting MagLev and MHD systems will be described concentrating on, above all, the electromagnetic aspect. Some programmes occurring throughout the world will be described. Magnetic levitated trains could be the new high speed transportation system for the 21st century. Intensive studies involving MagLev trains using superconductivity have been carried out in Japan since 1970. The construction of a 43 km long track is to be the next step. In 1991 a six year programme was launched in the United States to evaluate the performances of MagLev systems for transportation. The MHD (MagnetoHydroDynamic) offers some interesting advantages (efficiency, stealth characteristics, ...) for naval propulsion and increasing attention is being paid towards it nowadays. Japan is also up at the top with the tests of Yamato I, a 260 ton MHD propulsed ship. Depuis quelques années nous assistons à un redémarrage de programmes concernant la lévitation et la propulsion supraconductrices. Différents systèmes supraconducteurs de lévitation et de propulsion seront décrits en examinant plus particulièrement l'aspect électromagnétique. Quelques programmes à travers le monde seront abordés. Les trains à sustentation magnétique pourraient constituer un nouveau mode de transport terrestre à vitesse élevée (500 km/h) pour le 21^e siècle. Les japonais n'ont cessé de s'intéresser à ce système avec bobine supraconductrice. Ils envisagent un stade préindustriel avec la construction d'une ligne de 43 km. En 1991 un programme américain pour une durée de six ans a été lancé pour évaluer les performances des systèmes à lévitation pour le transport aux Etats Unis. La MHD (Magnéto- Hydro-Dynamique) présente des avantages intéressants pour la propulsion navale et un regain d'intérêt apparaît à l'heure actuelle. Le japon se situe là encore à la pointe des d

A Model for Prediction of Propulsion Power and Emissions – Tankers and Bulk Carriers

DEFF Research Database (Denmark)

Lützen, Marie; Kristensen, Hans Otto Holmegaard

To get an idea of the reduction in propulsion power and associated emissions by varying the speed and other ship design main parameters, a generic model for parameter studies of tankers and bulk carriers has been developed. With only a few input parameters of which the maximum deadweight capacity...... is the primary input a proposal for the main dimensions is made. Based on these dimensions and other ship particulars which are determined by the program the necessary installed propulsion power can be calculated. By adjusting the vessel design, i.e. the suggested main dimensions, and varying the speed...

Green Shipping Practices of Shipping Firms

Directory of Open Access Journals (Sweden)

Young-Tae Chang

2017-05-01

Full Text Available The primary objective of this study is to provide an empirical research using structural equation modeling to identify the factors that motivate shipping firms to adopt green shipping practices (GSP. Furthermore, it also examines if adopting GSP can enhance the shipping firms’ environmental and productivity performance. The findings show that shipping firms are motivated to adopt GSP mostly by industrial norms set by institutionalized associations. They are also motivated by customers’ demand for environmental friendliness and their own strategy to make good image. Unlike our expectation, government regulations and international environmental laws are not significant in influencing shipping firms to adopt GSP. Moreover, adoption of green shipping practices can improve the environmental and productivity performance of the shipping firms.

Dynamic analysis and design of air spring mounting system for marine propulsion system

Science.gov (United States)

He, Lin; Xu, Wei; Bu, Wenjun; Shi, Liang

2014-09-01

Marine propulsion unit (MPU) is one of the dominant vibration and noise sources onboard ship. Its vibration can be attenuated effectively by isolating MPU with low-frequency mounting system. But this is difficult to implement due to the stringent requirement of MPU alignment with the propulsion shafting. In this paper a novel air spring mounting system (ASMS) for propulsion system is proposed consisting of air spring subsystem, alignment control subsystem and safety protection subsystem. The load distribution optimization method and dynamic model of ASMS are presented. The factors that affect system stability and natural frequencies are analyzed, as well as the design measures to enhance system performance. A theoretical model is presented to estimate the isolation effect of ASMS. The monitoring model of alignment between MPU and propulsion shafting is established, followed by the alignment control algorithm and converge rule which assures the fast and uniform convergence of both air springs load distribution and alignment control process. Safety protection mechanism is designed to ensure that the MPU can operate safely in case of ASMS failure or other extreme circumstances. A scaled ASMS prototype is manufactured and tested on a special experimental setup. Experimental results validate the effectiveness of theoretical models and show that the performance of ASMS satisfies the operation requirements of MPU.

Development of Nuclear ship Engineering Simulation SYstem (NESSY)

International Nuclear Information System (INIS)

Kusunoki, Tsuyoshi; Kyouya, Masahiko; Takahashi, Teruo; Kobayashi, Hideo; Ochiai, Masa-aki; Hashidate, Kouji.

1993-11-01

NESSY has been developed for design studies of advanced marine reactors as a part of nuclear ship research and development since 1987. Engineering simulation model of the Mutsu, which is the first nuclear ship in Japan, was completed in March of 1993. In this report we concentration on detail description of softwares for Mutsu modeling. The aims of development of NESSY are as follows; (1) Assessment and confirmation on plant performance of an advanced marine reactor in each step of nuclear ship design (2) Development of abnormality diagnosis system and operator support system as a part of enhanced automization study, and study of human interface with hardware The characteristics of NESSY are the followings. (1) Total engineering simulation system simulate simultaneously ship motions, propulsion system behavior, and nuclear plant behavior under given weather and sea conditions. (2) Models based on physical theory as far as possible. (3) The simulator has high extensibility and flexibility. It is able to apply to other reactors, as the simulation model consists of the part of basic model and the part of plant data which are easy to change. After completion of Mutsu modeling, we are planning to utilize this system as one of design tools for an advanced marine reactor. (author)

Some considerations on the safety of nuclear ships

International Nuclear Information System (INIS)

Kuramoto, Masaaki

1978-01-01

For realizing the practical utilization of nuclear merchant ships, it is essential to gain their acceptance by maritime countries on an equal footing with conventional vessels, and to have the administrative procedures for their admission simplified. This, however cannot be expected to be attained overnight, and progressive measures will have to be adopted, to approach the ultimate goal step by step. The first step should be to demonstrate the safety of nuclear propulsion, for which nuclear ships must accumulate their mileages of safe service. The second important step is to simplify the procedures demanded of nuclear ships for access to ports, through the establishment of international safety standards and design criteria, the enforcement of safety measures covering the entrance of nuclear ships into ports, and the assurance of safety in he repair, inspection and refuelling operations of these ships. Among these measures, the considerations relevant to port entry are the subject of vital interest to both ship operators and port authorities

Navy Ship Propulsion Technologies: Options for Reducing Oil Use - Background for Congress

National Research Council Canada - National Science Library

O'Rourke, Ronald

2006-01-01

...%. The Navy has installed fuel-saving bulbous bows and stern flaps on many of its ships. Ship fuel use could be reduced by shifting to advanced turbine designs such as an intercooled recuperated (ICR) turbine...

Navy Ship Propulsion Technologies: Options for Reducing Oil Use - Background for Congress

National Research Council Canada - National Science Library

O'Rourke, Ronald

2006-01-01

...; and using sail and solar power. Reducing energy use on Navy ships. A 2001 study concluded that fitting a Navy cruiser with more energy-efficient electrical equipment could reduce the ship's fuel use by 10% to 25...

Is a 125,000 M3 class ship always an optimum for LNG carriers 7

International Nuclear Information System (INIS)

Grill, A.

1992-01-01

When making the inventory of LNG carriers built up to the present day, one can see that ships of 125 to 130,000 m 3 may be considered as a real standard. An increase of ship's size, together with a reduction of the number of ships required on a given trade, must lead to a reduction of transportation cost. It must also be possible to obtain a better correlation between available energy during voyage and propulsion needs by adjusting boil-off rate and adapting the tanks insulation coefficient. The presentation shows the possibility to significantly reduce LNG transportation cost by an optimization of the size for future ships. The study is based on a certain number of typical trades being able to be met when taking into account future foreseeable needs for LNG. The influence of parameters such as type of containment system and number of tanks, type of propulsion, influence of size restrictions, ability to deliver a given amount of LNG per year even in case of one ship temporary out of order is also considered

Numerical simulation of hydrodynamic performance of ship under oblique conditions

Directory of Open Access Journals (Sweden)

CHEN Zhiming

2018-02-01

Full Text Available [Objectives] This paper is intended to study the viscous flow field around a ship under oblique conditions and provide a research basis for ship maneuverability. [Methods] Using commercial software STRA-CCM+, the SST k-ω turbulence model is selected to predict the hydrodynamic performance of the KVLCC2 model at different drift angles, and predict the hull flow field. The pressure distribution of the ship model at different drift angles is observed and the vortex shedding of the ship's hull and constraint streamlines on the hull's surface are also observed. [Results] The results show that numerical simulation can satisfy the demands of engineering application in the prediction of the lateral force, yaw moment and hull surface pressure distribution of a ship. [Conclusions] The research results of this paper can provide valuable references for the study of the flow separation phenomenon under oblique conditions.

The circular form of the linear superconducting machine for marine propulsion

Science.gov (United States)

Rakels, J. H.; Mahtani, J. L.; Rhodes, R. G.

1981-01-01

The superconducting linear synchronous machine (LSM) is an efficient method of propulsion of advanced ground transport systems and can also be used in marine engineering for the propulsion of large commercial vessels, tankers, and military ships. It provides high torque at low shaft speeds and ease of reversibility; a circular LSM design is proposed as a drive motor. The equipment is compared with the superconducting homopolar motors, showing flexibility in design, built in redundancy features, and reliability.

Analysis of a ship-to-ship collision

International Nuclear Information System (INIS)

Porter, V.L.; Ammerman, D.J.

1996-01-01

Sandia National Laboratories is involved in a safety assessment for the shipment of radioactive material by sea. One part of this study is investigation of the consequences of ship-to-ship collisions. This paper describes two sets of finite element analyses performed to assess the structural response of a small freighter and the loading imparted to radioactive material (RAM) packages during several postulated collision scenarios with another ship. The first series of analyses was performed to evaluate the amount of penetration of the freighter hull by a striking ship of various masses and initial velocities. Although these analyses included a representation of a single RAM package, the package was not impacted during the collision so forces on the package could not be computed. Therefore, a second series of analyses incorporating a representation of a row of seven packages was performed to ensure direct package impact by the striking ship. Average forces on a package were evaluated for several initial velocities and masses of the striking ship. In addition to. providing insight to ship and package response during a few postulated ship collisions scenarios, these analyses will be used to benchmark simpler ship collision models used in probabilistic risk assessment analyses

Improving sustainability of maritime transport through utilization of Liquefied Natural Gas (LNG) for propulsion

International Nuclear Information System (INIS)

Burel, Fabio; Taccani, Rodolfo; Zuliani, Nicola

2013-01-01

Today, most merchant vessels use Heavy Fuel Oils (HFOs) for ship propulsion. These fuels are cost effective but they produce significant amounts of noxious emissions. In order to comply with International Maritime Organization (IMO) rules, Liquefied Natural Gas (LNG) is becoming an interesting option for merchant ships. The aim of the research presented in this paper is to analyse the economic upturn that can result from the use of LNG as fuel for merchant ships and to assess the effects of its utilization in terms of environmental impact. In the first part of the study, a statistical analysis of maritime traffic is carried out in order to identify which merchant ship types could most benefit from using LNG as fuel for ship propulsion. Traffic data of world ships related to the months of May 2008, 2009 and 2010 are analysed. Roll-on/Roll-off vessels (RoRo) and tanker ships spend most of their sailing time in Emission Control Areas (ECA) consequently appear to be the best candidates for LNG use. In particular, the use of LNG is most profitable for tanker ships in the range of 10,000–60,000 DWT (deadweight). In the second part of the study, operational costs and pollutant emission reduction, following LNG implementation, are calculated for a 33,000 DWT tanker ship. Results show that LNG leads to a reduction of 35% of operational costs and 25% of CO 2 emissions. The possibility of improving energy efficiency on board is analysed considering that combustion gases, produced by LNG, are cleaner, thus simplifying the introduction of exhaust gas heat recovery. Two options are considered: simple heat recovery and heat recovery to drive a turbine (ORC). The results show that it is possible to achieve a reduction in fuel consumption of up to 15%. - Highlights: • Ship propulsion accounts for a large amount of noxious emissions in costal/harbour areas. • Today price differential between fuel oil and natural gas is increasing. • The use of Liquefied Natural Gas as fuel

A Method to Assess Transverse Vibration Energy of Ship Propeller Shaft for Diagnostic Purposes

Directory of Open Access Journals (Sweden)

Korczewski Zbigniew

2017-12-01

Full Text Available The article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span point between the supports. To verify the developed model, pilot tests were performed on the laboratory rotational mechanical system test rig. In those tests, cyclic bending moment was applied to a unified (cylindrical material sample, which modelled, at an appropriate scale, structural and functional properties of a real propeller shaft.

State of the Japanese nuclear research ship MUTSU

International Nuclear Information System (INIS)

Lettnin, H.

1981-01-01

A short introductary comment of the German-Japanese cooperation on the field of nuclear ship propulsion is given, which since several years had led to the development of a nuclear propelled containership with 80 000 shp. Against this background the cooperation with the Japanese was renewed for checking the shield modification of NS MUTSU by GKSS. Before the modification of the shielding is dealt with in more detail the design concept of ship and reactor plant of the vessel is presented. The observed defects as well as the rebuilding concept of the changed shielding incl. the shielding calculations. The constructive modifications have led to reconsiderations of safety aspects for ship and reactor. Finally a short description of the repair site in Sasebo is given and an outlook on the nuclear ship development in Japan. (orig.) [de

The future of nuclear propulsion in merchant ships

International Nuclear Information System (INIS)

Young, R.T.

1977-01-01

Attention is paid to a number of issues which must be resolved before any firm commitment to build a commercial nuclear powered ship will be made. Basically, these can be grouped into three major problem areas: first, economic; second, indemnification and liability; and third, port entry and international clearance. It is concluded that there is reason for guarded optimism, as concerted efforts to solve the important issues are now underway. Some examples are briefly discussed

Performance of flapping airfoil propulsion with LBM method and DMD analysis

Science.gov (United States)

Li, Bing-Hua; Huang, Xian-Wen; Zheng, Yao; Xie, Fang-Fang; Wang, Jing; Zou, Jian-Feng

2018-05-01

In this work, the performance of flapping airfoil propulsion at low Reynolds number of Re = 100-400 is studied numerically with the lattice Boltzmann method (LBM). Combined with immersed boundary method (IBM), the LBM has been widely used to simulate moving boundary problems. The influences of the reduced frequency on the plunging and pitching airfoil are explored. It is found that the leading-edge vertex separation and inverted wake structures are two main coherent structures, which dominate the flapping airfoil propulsion. However, the two structures play different roles in the flow and the combination effects on the propulsion need to be clarified. To do so, we adopt the dynamic mode decomposition (DMD) algorithm to reveal the underlying physics. The DMD has been proven to be very suitable for analyzing the complex transient systems like the vortex structure of flapping flight.

Model of a Nuclear Security Naval Agency for radiation control of the Industrial Complex of of Submarine Construction and Maintenance Ship with Nuclear Propulsion

International Nuclear Information System (INIS)

Lins Junior, Amilton de Sousa

2017-01-01

Due to the construction, by Brazilian Navy, of a Submarine Construction and Maintenance Ship with Nuclear Propulsion, where, among other activities, the commissioning and exchange of the fuel elements of the reactor in the future Nuclear Submarine, and of a Naval Base where the Nuclear Submarine and the Conventional Submarines, it is necessary the establishment of a Nuclear Security Naval Agency to monitor activities involving ionizing radiation sources and nuclear materials aimed at the radiological protection of exposed occupationally individuals (IOE), the general public and the environment. It should be noted that nuclear and radioactive material will be present only in a part of the yard called Radiological Complex. Therefore, the development of a structure for the control of the Radiological Complex is fundamental, considering that the future licensing process will be unprecedented in Brazil and will face several difficulties. This work presents a model of a structure for the radiological control of the industrial complex for the construction and maintenance of the submarine with nuclear propulsion, as well as the fundamental concepts of the activities, such as inspection, regulations and authorizations, to be carried out by the various component sectors of the Nuclear Security Naval Agency. (author)

Frequency Transient Suppression in Hybrid Electric Ship Power Systems: A Model Predictive Control Strategy for Converter Control with Energy Storage

Directory of Open Access Journals (Sweden)

Viknash Shagar

2018-03-01

Full Text Available This paper aims to understand how the common phenomenon of fluctuations in propulsion and service load demand contribute to frequency transients in hybrid electric ship power systems. These fluctuations arise mainly due to changes in sea conditions resulting in significant variations in the propulsion load demand of ships. This leads to poor power quality for the power system that can potentially cause hazardous conditions such as blackout on board the ship. Effects of these fluctuations are analysed using a hybrid electric ship power system model and a proposed Model Predictive Control (MPC strategy to prevent propagation of transients from the propellers into the shipboard power system. A battery energy storage system, which is directly connected to the DC-link of the frequency converter, is used as the smoothing element. Case studies that involve propulsion and service load changes have been carried out to investigate the efficacy of the proposed solution. Simulation results show that the proposed solution with energy storage and MPC is able to contain frequency transients in the shipboard power system within the permissible levels stipulated by the relevant power quality standards. These findings will help ship builders and operators to consider using battery energy storage systems controlled by advanced control techniques such as MPC to improve the power quality on board ships.

Recent Advances in Airframe-Propulsion Concepts with Distributed Propulsion

OpenAIRE

Isikveren , A.T.; Seitz , A.; Bijewitz , J.; Hornung , M.; Mirzoyan , A.; Isyanov , A.; Godard , J.L.; Stückl , S.; Van Toor , J.

2014-01-01

International audience; This paper discusses design and integration associated with distributed propulsion as a means of providing motive power for future aircraft concepts. The technical work reflects activities performed within a European Commission funded Framework 7 project entitled Distributed Propulsion and Ultra-high By-Pass Rotor Study at Aircraft Level, or, DisPURSAL. In this instance, the approach of distributed propulsion includes one unique solution that integrates the fuselage wi...

Assessing the potential of hybrid energy technology to reduce exhaust emissions from global shipping

International Nuclear Information System (INIS)

Dedes, Eleftherios K.; Hudson, Dominic A.; Turnock, Stephen R.

2012-01-01

The combination of a prime mover and an energy storage device for reduction of fuel consumption has successfully been used in automotive industry. The shipping industry has utilised this for conventional submarines. The potential of a load levelling strategy through use of a hybrid battery–diesel–electric propulsion system is investigated. The goal is to reduce exhaust gas emissions by reducing fuel oil consumption through consideration of a re-engineered ship propulsion system. This work is based on operational data for a shipping fleet containing all types of bulk carriers. The engine loading and the energy requirements are calculated, and sizing of suitable propulsion and the battery storage system are proposed. The changes in overall emissions are estimated and the potential for fuel savings identified. The efficiency of the system depends on the storage medium type, the availability of energy and the displacement characteristics of the examined vessels. These results for the global fleet indicate that savings depending on storage system, vessel condition and vessel type could be up to 0.32 million tonnes in NO x , 0.07 million tonnes in SO x and 4.1 million tonnes in CO 2 . These represent a maximum 14% of reduction in dry bulk sector and 1.8% of world's fleet emissions. - Highlights: ► Global shipping makes a significant contribution to CO 2 , SO x and NO x emissions. ► We examine noon reports from a fleet of bulk carriers to identify the amount engine is operating off design. ► A hybrid propulsion system is proposed that uses multiple diesel–electric generators and battery storage. ► Analysis indicates hybrid may give an attractive rate of return as well as emissions savings in emissions. ► Implementation will require review of class society regulations.

Prediction of Full-Scale Propulsion Power using Artificial Neural Networks

DEFF Research Database (Denmark)

Pedersen, Benjamin Pjedsted; Larsen, Jan

2009-01-01

Full scale measurements of the propulsion power, ship speed, wind speed and direction, sea and air temperature from four different loading conditions, together with hind cast data of wind and sea properties; and noon report data has been used to train an Artificial Neural Network for prediction...

A decision support system for mission-based ship routing considering multiple performance criteria

International Nuclear Information System (INIS)

Dong, You; Frangopol, Dan M.; Sabatino, Samantha

2016-01-01

It is crucial to evaluate the risk associated with marine vessels subjected to inclement weather and sea conditions when developing a decision support system for ship routing. The generalized decision making framework developed in this paper performs a variety of tasks, including, but not limited to quantifying the flexural and fatigue performance of ship structures and employing multi-attribute utility theory to evaluate ship mission performance. A structural reliability approach is utilized to compute the probability of failure considering the uncertainties in structural capacity and load effects; specifically, effects of flexural and fatigue damage are investigated. The expected repair cost, cumulative fatigue damage, total travel time, and carbon dioxide emissions associated with ship routing are considered as consequences within the risk assessment procedure adopted in this paper. Additionally, the decision maker’s risk attitude is integrated into the presented approach by employing utility theory. The presented methodology can assist decision makers in making informed decisions concerning ship routing. In order to illustrate its capabilities the approach is applied to the Joint High-speed Sealift Ship. - Highlights: • Multi-attribute utility theory is proposed for the ship routing decision making. • Spectral-based fatigue damage and repair loss are computed. • Travel time and CO_2 emissions are incorporated within the decision making process. • The attitude of the decision maker has significant effects on the utility value.

State of the Japanese nuclear research ship MUTSU

International Nuclear Information System (INIS)

Lettnin, H.

1981-01-01

A short introductory comment of the German-Japanese cooperation on the field of nuclear ship propulsion is given, which since several years had led to the development of a nuclear propelled containership with 80 000 shp. Against this background the cooperation with the Japanese was renewed for checking the shield modification of NS MUTSU by GKSS. Before the modification of the shielding is dealt with in more detail the design concept of ship and reactor plant of the vessel is presented. The observed defects in the shielding during the nuclear commissioning of the vessel are discussed as well as the rebuilding concept of the changed shielding incl. the shielding calculations. The constructive modifications have led to reconsiderations of safety aspects for ship and reactor. Finally a short description of the repair site in Sasebo is given and an outlook on the nuclear ship development in Japan. (orig.) [de

A Novel Approach to Turbulence Stimulation for Ship-Model Testing

Science.gov (United States)

2010-05-11

a given hull form. As van Manen and van Oossanen note, ship resistance is related to “the proportions and shape… of the hull, the size and type of...propulsion plant to provide motive power, and the device or system to transform the power into effective thrust” ( van Manen and van Oossanen, 1988...what is known as the Ship-Model Tester’s Dilemma, which van Manen and van Oossanen define as “the conditions of mechanical similitude for both friction

Green shipping management

CERN Document Server

Lun, Y H Venus; Wong, Christina W Y; Cheng, T C E

2016-01-01

This book presents theory-driven discussion on the link between implementing green shipping practices (GSP) and shipping firm performance. It examines the shipping industry’s challenge of supporting economic growth while enhancing environmental performance. Consisting of nine chapters, the book covers topics such as the conceptualization of green shipping practices (GSPs), measurement scales for evaluating GSP implementation, greening capability, greening and performance relativity (GPR), green management practice, green shipping network, greening capacity, and greening propensity. In view of the increasing quest for environment protection in the shipping sector, this book provides a good reference for firms to understand and evaluate their capability in carrying out green operations on their shipping activities.

Code of safety for nuclear merchant ships

International Nuclear Information System (INIS)

1982-01-01

The Code is in chapters, entitled: general (including general safety principles and principles of risk acceptance); design criteria and conditions; ship design, construction and equipment; nuclear steam supply system; machinery and electrical installations; radiation safety (including radiological protection design; protection of persons; dosimetry; radioactive waste management); operation (including emergency operation procedures); surveys. Appendices cover: sinking velocity calculations; seaway loads depending on service periods; safety assessment; limiting dose-equivalent rates for different areas and spaces; quality assurance programme; application of single failure criterion. Initial application of the Code is restricted to conventional types of ships propelled by nuclear propulsion plants with pressurized light water type reactors. (U.K.)

Effects of shape and stroke parameters on the propulsion performance of an axisymmetric swimmer.

Science.gov (United States)

Peng, Jifeng; Alben, Silas

2012-03-01

In nature, there exists a special group of aquatic animals which have an axisymmetric body and whose primary swimming mechanism is to use periodic body contractions to generate vortex rings in the surrounding fluid. Using jellyfish medusae as an example, this study develops a mathematical model of body kinematics of an axisymmetric swimmer and uses a computational approach to investigate the induced vortex wakes. Wake characteristics are identified for swimmers using jet propulsion and rowing, two mechanisms identified in previous studies of medusan propulsion. The parameter space of body kinematics is explored through four quantities: a measure of body shape, stroke amplitude, the ratio between body contraction duration and extension duration, and the pulsing frequency. The effects of these parameters on thrust, input power requirement and circulation production are quantified. Two metrics, cruising speed and energy cost of locomotion, are used to evaluate the propulsion performance. The study finds that a more prolate-shaped swimmer with larger stroke amplitudes is able to swim faster, but its cost of locomotion is also higher. In contrast, a more oblate-shaped swimmer with smaller stroke amplitudes uses less energy for its locomotion, but swims more slowly. Compared with symmetric strokes with equal durations of contraction and extension, faster bell contractions increase the swimming speed whereas faster bell extensions decrease it, but both require a larger energy input. This study shows that besides the well-studied correlations between medusan body shape and locomotion, stroke variables also affect the propulsion performance. It provides a framework for comparing the propulsion performance of axisymmetric swimmers based on their body kinematics when it is difficult to measure and analyze their wakes empirically. The knowledge from this study is also useful for the design of robotic swimmers that use axisymmetric body contractions for propulsion.

Effects of shape and stroke parameters on the propulsion performance of an axisymmetric swimmer

International Nuclear Information System (INIS)

Peng Jifeng; Alben, Silas

2012-01-01

In nature, there exists a special group of aquatic animals which have an axisymmetric body and whose primary swimming mechanism is to use periodic body contractions to generate vortex rings in the surrounding fluid. Using jellyfish medusae as an example, this study develops a mathematical model of body kinematics of an axisymmetric swimmer and uses a computational approach to investigate the induced vortex wakes. Wake characteristics are identified for swimmers using jet propulsion and rowing, two mechanisms identified in previous studies of medusan propulsion. The parameter space of body kinematics is explored through four quantities: a measure of body shape, stroke amplitude, the ratio between body contraction duration and extension duration, and the pulsing frequency. The effects of these parameters on thrust, input power requirement and circulation production are quantified. Two metrics, cruising speed and energy cost of locomotion, are used to evaluate the propulsion performance. The study finds that a more prolate-shaped swimmer with larger stroke amplitudes is able to swim faster, but its cost of locomotion is also higher. In contrast, a more oblate-shaped swimmer with smaller stroke amplitudes uses less energy for its locomotion, but swims more slowly. Compared with symmetric strokes with equal durations of contraction and extension, faster bell contractions increase the swimming speed whereas faster bell extensions decrease it, but both require a larger energy input. This study shows that besides the well-studied correlations between medusan body shape and locomotion, stroke variables also affect the propulsion performance. It provides a framework for comparing the propulsion performance of axisymmetric swimmers based on their body kinematics when it is difficult to measure and analyze their wakes empirically. The knowledge from this study is also useful for the design of robotic swimmers that use axisymmetric body contractions for propulsion. (paper)

An electric vehicle propulsion system's impact on battery performance: An overview

Science.gov (United States)

Bozek, J. M.; Smithrick, J. J.; Cataldo, R. C.; Ewashinka, J. G.

1980-01-01

The performance of two types of batteries, lead-acid and nickel-zinc, was measured as a function of the charging and discharging demands anticipated from electric vehicle propulsion systems. The benefits of rapid high current charging were mixed: although it allowed quick charges, the energy efficiency was reduced. For low power (overnight) charging the current wave shapes delivered by the charger to the battery tended to have no effect on the battery cycle life. The use of chopper speed controllers with series traction motors resulted in a significant reduction in the energy available from a battery whenever the motor operates at part load. The demand placed on a battery by an electric vehicle propulsion system containing electrical regenerative braking confirmed significant improvment in short term performance of the battery.

Decommissioning plan of the nuclear-powered ship 'Mutsu'

International Nuclear Information System (INIS)

1992-01-01

The nuclear-powered ship 'Mutsu' is to be decommissioned at Sekinehama Port immediately after finishing the experimental voyage based on the 'Fundamental plan on the research required for the development of nuclear ships in Japan Atomic Energy Research Institute' decided in March, 1985. The decommissioning plan which determines the methods of the works regarding the decommissioning and others is as follows. In order to utilize the ship hull of Mutsu, the reactor room including the reactor and shielding is removed in a lump, and the removal and isolation method of preserving it as it is on land is adopted. The measures for environment preservation and ensuring the safety of residents are taken, and the sufficient work control is carried out for preventing accidents and reducing the radiation exposure of workers. The ship is used as the ship with ordinary propulsion system for ocean research and the research and development of marine reactors. The utilization of Sekinehama and Ominato facilities is investigated. The reactor room removed from Mutsu is exhibited to public, being preserved safely in a building. (K.I.)

Comparisons of Hydraulic Performance in Permanent Maglev Pump for Water-Jet Propulsion

Directory of Open Access Journals (Sweden)

Puyu Cao

2014-08-01

Full Text Available The operation of water-jet propulsion can generate nonuniform inflow that may be detrimental to the performance of the water-jets. To reduce disadvantages of the nonuniform inflow, a rim-driven water-jet propulsion was designed depending on the technology of passive magnetic levitation. Insufficient understanding of large performance deviations between the normal water-jets (shaft and permanent maglev water-jets (shaftless is a major problem in this paper. CFD was directly adopted in the feasibility and superiority of permanent maglev water-jets. Comparison and discussion of the hydraulic performance were carried out. The shaftless duct firstly has a drop in hydraulic losses (K1, since it effectively avoids the formation and evolution of the instability secondary vortex by the normalized helicity analysis. Then, the shaftless intake duct improves the inflow field of the water-jet pump, with consequencing the drop in the backflow and blocking on the blade shroud. So that the shaftless water-jet pump delivers higher flow rate and head to the propulsion than the shaft. Eventually, not only can the shaftless model increase the thrust and efficiency, but it has the ability to extend the working range and broaden the high efficiency region as well.

Historic survey on nuclear merchant ships

Energy Technology Data Exchange (ETDEWEB)

Freire, Luciano Ondir, E-mail: luciano.ondir@gmail.com; Andrade, Delvonei Alves de, E-mail: delvonei@ipen.br

2015-11-15

Highlights: • The nuclear merchants ships already built are described and studied. • Their history and main architectural choices are presented, focusing nuclear domain. • The typical problems in those projects are discussed. • Some key factors for developing successful nuclear merchant ships are identified. - Abstract: This work provides a survey on past nuclear merchant ships experience. On light of new regulations on CO{sub 2}, SO{sub x} and NO{sub x}, the options for clean naval propulsion need to be studied. Despite many efforts, the only already sea proven emissions-free energy is nuclear power of pressurized water reactor type. Given the past experience on the field, this work provides some information on history, architectures and hints of reasons for the success or failures of each project. It is found that adequate requirements identification must be done keeping economics always in the center of design. Experience shows, except after major catastrophic accidents, public trust may be earned by open dialog and sound engineering practices.

Historic survey on nuclear merchant ships

International Nuclear Information System (INIS)

Freire, Luciano Ondir; Andrade, Delvonei Alves de

2015-01-01

Highlights: • The nuclear merchants ships already built are described and studied. • Their history and main architectural choices are presented, focusing nuclear domain. • The typical problems in those projects are discussed. • Some key factors for developing successful nuclear merchant ships are identified. - Abstract: This work provides a survey on past nuclear merchant ships experience. On light of new regulations on CO 2 , SO x and NO x , the options for clean naval propulsion need to be studied. Despite many efforts, the only already sea proven emissions-free energy is nuclear power of pressurized water reactor type. Given the past experience on the field, this work provides some information on history, architectures and hints of reasons for the success or failures of each project. It is found that adequate requirements identification must be done keeping economics always in the center of design. Experience shows, except after major catastrophic accidents, public trust may be earned by open dialog and sound engineering practices.

Numerical Ship Hydrodynamics : an assessment of the Gothenburg 2010 Workshop

CERN Document Server

Stern, Frederick; Visonneau, Michel

2014-01-01

This book assesses the state-of-the-art in computational fluid dynamics (CFD) applied to ship hydrodynamics and provides guidelines for the future developments in the field based on the Gothenburg 2010 Workshop. It presents ship hull test cases, experimental data and submitted computational methods, conditions, grids and results.  Analysis is made of errors for global (resistance, sinkage and trim and self-propulsion) and local flow (wave elevations and mean velocities and turbulence) variables, including standard deviations for global variables and propeller modeling for self-propulsion. The effects of grid size and turbulence models are evaluated for both global and local flow variables. Detailed analysis is made of turbulence modeling capabilities for capturing local flow physics. Errors are also analyzed for head-wave seakeeping and forward speed diffraction, and calm-water forward speed-roll decay. Resistance submissions are used to evaluate the error and uncertainty by means of a systematic verificatio...

The Impact of Analog and Bang-Bang Steering Gear Control on Ship's Fuel Economy

DEFF Research Database (Denmark)

Nørtoft Thomsen, J. C.; Blanke, Mogens; Reid, R. E.

1982-01-01

it is found to be at least equally important regarding steering performance and fuel economy. The paper presents a comprehensive survey of steering gear principles commonly used, including relevant details of three analog steering gear servo principles, which have outperformed conventional designs. Control......The latest years have shown considerable efforts towards improving steering generated propulsion losses of ships by the introduction of various sophisticated control algorithms in the autopilots. However, little previous attention has been given to the steering gear control loop, although...

Application of fuel cells in surface ships

Energy Technology Data Exchange (ETDEWEB)

Bourne, C.; Nietsch, T.; Griffiths, D.; Morley, J.

2001-07-01

This report presents the findings of a DTI supported project entitled: ''Applications of fuel cells in surface ships''. It gives a brief market analysis describing the general requirements of different vessel types and an overview of the different heat engine technologies currently used for propulsion and power generation in ships. The appendices contain a more detailed description of the different vessel types, their general requirements and a description of current prime mover technologies used. This analysis is followed by a summary of the major fuel cell development programmes and activities ongoing in different countries that have a direct or potential relevance to a marine application of the technology. (author)

Flow measurement around a model ship with propeller and rudder

Energy Technology Data Exchange (ETDEWEB)

Van, S H; Yoon, H S; Lee, Y Y; Park, I R [Korea Research Institute of Ships and Ocean Engineering, KORDI, Marine Transportation Systems Laboratory, Daejeon (Korea); Kim, W J [Mokpo National University, Department of Naval Architecture and Marine Engineering, Jeonnam (Korea)

2006-04-15

For the design of hull forms with better resistance and propulsive performance, it is essential to understand flow characteristics, such as wave and wake development, around a ship. Experimental data detailing the local flow characteristics are invaluable for the validation of the physical and numerical modeling of computational fluid dynamics (CFD) codes, which are recently gaining attention as efficient tools for hull form evaluation. This paper describes velocity and wave profiles measured in the towing tank for the KRISO 138,000 m{sup 3} LNG carrier model with propeller and rudder. The effects of propeller and rudder on the wake and wave profiles in the stern region are clearly identified. The results contained in this paper can provide an opportunity to explore integrated flow phenomena around a model ship in the self-propelled condition, and can be added to the International Towing Tank Conference benchmark data for CFD validation as the previous KCS and KVLCC cases. (orig.)

Flow measurement around a model ship with propeller and rudder

Science.gov (United States)

van, S. H.; Kim, W. J.; Yoon, H. S.; Lee, Y. Y.; Park, I. R.

2006-04-01

For the design of hull forms with better resistance and propulsive performance, it is essential to understand flow characteristics, such as wave and wake development, around a ship. Experimental data detailing the local flow characteristics are invaluable for the validation of the physical and numerical modeling of computational fluid dynamics (CFD) codes, which are recently gaining attention as efficient tools for hull form evaluation. This paper describes velocity and wave profiles measured in the towing tank for the KRISO 138,000 m3 LNG carrier model with propeller and rudder. The effects of propeller and rudder on the wake and wave profiles in the stern region are clearly identified. The results contained in this paper can provide an opportunity to explore integrated flow phenomena around a model ship in the self-propelled condition, and can be added to the International Towing Tank Conference benchmark data for CFD validation as the previous KCS and KVLCC cases.

Hydromechanics of Wind-Assisted Ship Propulsion : Modeling of Hydrodynamic Sideforce

NARCIS (Netherlands)

van der Kolk, N.J.

2016-01-01

This paper deals with the hydrodynamic sideforce production of a wind-assisted ship. The subject is introduced, both in physical terms, and with an overview of current and recent work. The importance of the hydrodynamic sideforce is established, before classical models are reviewed. Finally, the

Extended performance electric propulsion power processor design study. Volume 2: Technical summary

Science.gov (United States)

Biess, J. J.; Inouye, L. Y.; Schoenfeld, A. D.

1977-01-01

Electric propulsion power processor technology has processed during the past decade to the point that it is considered ready for application. Several power processor design concepts were evaluated and compared. Emphasis was placed on a 30 cm ion thruster power processor with a beam power rating supply of 2.2KW to 10KW for the main propulsion power stage. Extension in power processor performance were defined and were designed in sufficient detail to determine efficiency, component weight, part count, reliability and thermal control. A detail design was performed on a microprocessor as the thyristor power processor controller. A reliability analysis was performed to evaluate the effect of the control electronics redesign. Preliminary electrical design, mechanical design and thermal analysis were performed on a 6KW power transformer for the beam supply. Bi-Mod mechanical, structural and thermal control configurations were evaluated for the power processor and preliminary estimates of mechanical weight were determined.

A Cost-effective and Emission-aware Power Management System for Ships with Integrated Full Electric Propulsion

DEFF Research Database (Denmark)

Kanellos, Fotis D.; Anvari-Moghaddam, Amjad; Guerrero, Josep M.

2017-01-01

The extensive exploitation of electric power in ships enables the development of more efficient and environmentally friendlier ships, as it allows for a more flexible ship power system operation and configuration. In this paper, an optimal power management method for ship electric power systems....... The proposed fuzzy-based particle swarm optimization (FPSO) algorithm aims at minimizing the operation cost, limiting the greenhouse gas (GHG) emissions and satisfying the technical and operational constraints of the ship....

IMPLEMENTATION APPROACHES DURING SIMULATION OF ENERGY PROCESSES FOR A DYNAMICALLY POSITIONED SHIP

Directory of Open Access Journals (Sweden)

V.V. Budashko

2015-12-01

Full Text Available Purpose. Creation of a mathematical model of the ship's power plant (SPP combined propulsion complexes (CPC that takes into account the behavior of all objects, including the ship itself, the transfer of power from the medium speed diesel generators on the propellers, which will allow to take into account the hydrodynamic properties of the vessel and their impact on the energy processes in SPP CPC. Methodology. The analysis of energy processes in the SPP CPC in different operating conditions resulted in creation of a strategy for constructing mathematical models of SPP CPC. This strategy is based on the implementation on the vector plane resulting power characteristics of SPP vectors disturbances, leading to the deviation of the hydrodynamic characteristics of the ship during operation dynamic positioning. The result allowed to consider not only the features of setting PID-governors of frequency converters of electric thrusters but the automatic voltage regulators of medium speed diesel generators as well. Results. Within the research work a software package Ships_CPC in MatLab/Simulink was developed under the state budget project «Concepts, technologies and ways of improving ship power plants combined propulsion complexes» at the Department of Electromechanics and Electrical Engineering of Odessa National Maritime Academy. Originality. This complex represents a set of functional blocks of the components SPP CPC, built on the principle of «input-output». The simulation results demonstrate the ability to use software package Ships_CPC to study the effect of various settings on the energy regulators of processes SPP CPC, which can develop and integrate the different strategies of automatic voltage regulators. Practical value. Since software complex Ships_CPC was developed under Open system technology, it can reorganize, re-tune and integrate in processes of any difficulties with further completion in the form of a universal structure.

Titan I propulsion system modeling and possible performance improvements

Science.gov (United States)

Giusti, Oreste

This thesis features the Titan I propulsion systems and offers data-supported suggestions for improvements to increase performance. The original propulsion systems were modeled both graphically in CAD and via equations. Due to the limited availability of published information, it was necessary to create a more detailed, secondary set of models. Various engineering equations---pertinent to rocket engine design---were implemented in order to generate the desired extra detail. This study describes how these new models were then imported into the ESI CFD Suite. Various parameters are applied to these imported models as inputs that include, for example, bi-propellant combinations, pressure, temperatures, and mass flow rates. The results were then processed with ESI VIEW, which is visualization software. The output files were analyzed for forces in the nozzle, and various results were generated, including sea level thrust and ISP. Experimental data are provided to compare the original engine configuration models to the derivative suggested improvement models.

Parametric study of propeller boss cap fins for container ships

Science.gov (United States)

Lim, Sang-Seop; Kim, Tae-Won; Lee, Dong-Myung; Kang, Chung-Gil; Kim, Soo-Young

2014-06-01

The global price of oil, which is both finite and limited in quantity, has been rising steadily because of the increasing requirements for energy in both developing and developed countries. Furthermore, regulations have been strengthened across all industries to address global warming. Many studies of hull resistance, propulsion and operation of ships have been performed to reduce fuel consumption and emissions. This study examined the design parameters of the propeller boss cap fin (PBCF) and hub cap for 6,000TEU container ships to improve the propulsion efficiency. The design parameters of PBCF have been selected based on the geometrical shape. Computational fluid dynamics (CFD) analysis with a propeller open water (POW) test was performed to check the validity of CFD analysis. The design of experiment (DOE) case was selected as a full factorial design, and the experiment was analyzed by POW and CFD analysis. Analysis of variance (ANOVA) was performed to determine the correlation among design parameters. Four design alternatives of PBCF were selected from the DOE. The shape of a propeller hub cap was selected as a divergent shape, and the divergent angle was determined by the DOE. Four design alternatives of PBCF were attached to the divergent hub cap, and the POW was estimated by CFD. As a result, the divergent hub cap with PBCF has a negative effect on the POW, which is induced by an increase in torque coefficient. A POW test and cavitation test were performed with a divergent hub cap with PBCF to verify the CFD result. The POW test result showed that the open water efficiency was increased approximately 2% with a divergent hub cap compared to a normal cap. The POW test result was similar to the CFD result, and the divergent hub cap with the PBCF models showed lower open water efficiency. This was attributed to an increase in the torque coefficient just like the CFD results. A cavitation test was performed using the 2 models selected. The test result showed

The MOA thruster. A high performance plasma accelerator for nuclear power and propulsion applications

International Nuclear Information System (INIS)

Frischauf, Norbert; Hettmer, Manfred; Grassauer, Andreas; Bartusch, Tobias; Koudelka, Otto

2009-01-01

More than 60 years after the late Nobel laureate Hannes Alfven had published a letter stating that oscillating magnetic fields can accelerate ionised matter via magneto-hydrodynamic interactions in a wave like fashion, the technical implementation of Alfven waves for propulsive purposes has been proposed, patented and examined for the first time by a group of inventors. The name of the concept, utilising Alfven waves to accelerate ionised matter for propulsive purposes, is MOA - Magnetic field Oscillating Amplified thruster. Alfven waves are generated by making use of two coils, one being permanently powered and serving also as magnetic nozzle, the other one being switched on and off in a cyclic way, deforming the field lines of the overall system. It is this deformation that generates Alfven waves, which are in the next step used to transport and compress the propulsive medium, in theory leading to a propulsion system with a much higher performance than any other electric propulsion system. While space propulsion is expected to be the prime application for MOA and is supported by numerous applications such as Solar and/or Nuclear Electric Propulsion or even as an 'afterburner system' for Nuclear Thermal Propulsion, other, terrestrial applications, like coating, semiconductor implantation and manufacturing as well as steel cutting can be thought of as well, making the system highly suited for a common space-terrestrial application research and utilisation strategy. This paper presents the recent developments of the MOA Thruster R and D activities at QASAR, the company in Vienna, Austria, which has been set up to further develop and test the Alfven wave technology and its applications. (author)

Nuclear-microwave-electric propulsion

International Nuclear Information System (INIS)

Nordley, G.D.; Brown, W.C.

1986-01-01

Electric propulsion can move more mass through space than chemical propulsion by virtue of the higher exhaust velocities achieved by electric propulsion devices. This performance is achieved at the expense of very heavy power sources or very long trip times, which in turn create technical and economic penalties of varying severity. These penalties include: higher operations costs, delayed availability of the payload, and increased exposure to Van Allen Belt radiation. It is proposed to reduce these penalties by physically separating the power source from the propulsion and use microwave energy beaming technology, recently explored and partially developed/tested for Solar Power Satellite concept studies, as an extension cord. This paper summarizes the state of the art of the technology needed for space based beam microwave power cost/performance trades involved with the use beamed microwave/electric propulsion for some typical orbit transfer missions and offers some suggestions for additional work

Ship Benchmark Shaft and Engine Gain FDI Using Neural Network

DEFF Research Database (Denmark)

Bendtsen, Jan Dimon; Izadi-Zamanabadi, Roozbeh

2002-01-01

threshold value. In the paper a method for determining this threshold based on the neural network model is proposed, which can be used for a design strategy to handle residual sensitivity to input variations. The proposed method is used for successful FDI of a diesel engine gain fault in a ship propulsion...

Contribution to the use of a solid moderator gas reactor, for naval propulsion; Contribution a l'etude d'un reacteur a gaz, a moderateur solide, pour propulsion navale

Energy Technology Data Exchange (ETDEWEB)

Pheline, J.; Gautier, A.

1960-01-04

In this contribution, the authors discuss works performed in France for the development of nuclear propulsion in merchant ships, notably for an oil tanker of 50.000 tons with 17 knot speed, i.e. a 20.000 Hp engine with an energy produced by a 60 MW gas reactor with a solid moderator and comprising 400 channels loaded with uranium oxide enriched ay 2.8 per cent and sheathed with a refractory alloy. The authors discuss the possible materials for the moderator, the heat transfer medium, the sheath, the fuel and the structures, and report technological studies (mechanical tests, irradiation tests) performed to investigate material properties and their behaviour in operation conditions. They report tests performed to investigate core structure characteristics with respect to neutrons. They finally briefly present a prototype.

Optimum cycle frequencies in hand-rim wheelchair propulsion. Wheelchair propulsion technique

NARCIS (Netherlands)

van der Woude, L H; Veeger, DirkJan (H. E. J.); Rozendal, R H; Sargeant, A J

1989-01-01

To study the effect of different cycle frequencies on cardio-respiratory responses and propulsion technique in hand-rim wheelchair propulsion, experienced wheelchair sportsmen (WS group; n = 6) and non-wheelchair users (NW group; n = 6) performed wheelchair exercise tests on a motor-driven

Design and Performance of the NASA SCEPTOR Distributed Electric Propulsion Flight Demonstrator

Science.gov (United States)

Borer, Nicholas K.; Patterson, Michael D.; Viken, Jeffrey K.; Moore, Mark D.; Clarke, Sean; Redifer, Matthew E.; Christie, Robert J.; Stoll, Alex M.; Dubois, Arthur; Bevirt, JoeBen;

Submaximal physical strain and peak performance in handcycling versus handrim wheelchair propulsion

NARCIS (Netherlands)

Dallmeijer, A.J.; Zentgraaff, I.D.; Zijp, N.I.; van der Woude, L.H.V.

2004-01-01

Study design: Experimental study in subjects with paraplegia and nondisabled subjects. Objective: To compare submaximal physical strain and peak performance in handcycling and handrim wheelchair propulsion in wheelchair-dependent and nondisabled control subjects Setting: Amsterdam, The Netherlands.

Enhancing human performance in ship operations by modifying global design factors at the design stage

International Nuclear Information System (INIS)

Montewka, Jakub; Goerlandt, Floris; Innes-Jones, Gemma; Owen, Douglas; Hifi, Yasmine; Puisa, Romanas

2017-01-01

Usually the improvements of human performance in the course of ship design process is carried out by modifying local ergonomics, like electronic visualisation and information display systems on the bridge or in the engine control room, stair or hatch covers design. However, the effect of global design factors (GDFs), such as ship motion, whole body vibration and noise, on human performance has not been given attention before. Such knowledge would allow the improvements of human performance by effective design modification on very early stage of ship design process. Therefore, in this paper we introduce probabilistic models linking the effect of GDFs with the human performance suitable for ship design process. As a theoretical basis for modelling human performance the concept of Attention Management is utilized, which combines the theories described by Dynamic Adaptability Model, Cognitive Control Model and Malleable Attentional Resources Theory. Since the analysed field is characterised by a high degree of uncertainty, we adopt a specific modelling technique along with a validation framework that allows uncertainty treatment and helps the potential end-users to gain confidence in the models and the results that they yield. The proposed models are developed with the use Bayesian Belief Networks, which allows systematic translation of the available background knowledge into a coherent network and the uncertainty assessment and treatment. The obtained results are promising as the models are responsive to changes in the GDF nodes as expected. The models may be used as intended by naval architects and vessel designers, to facilitate risk-based ship design. - Highlights: • Models linking the effect of GDFs with the human performance are established. • Three global design factors (GDFs) are considered: ship motion, body vibration, noise. • Attention Management concept as theoretical base is modelled with Bayesian Networks. • Two models are developed that can be

NS OTTO HAHN - the first German nuclear ship

International Nuclear Information System (INIS)

1981-01-01

The NS OTTO HAHN is the first and only European nuclear propelled cargo and research vessel. She entered service in 1968 and was operated for 11 years without any technical failure. The essential experience and know-how about the nuclear propulsion unit is available now. Therefore the ship was decommissioned in 1979. Until the end of 1981 all activated and contaminated components will be removed and decontaminated. The ship can then be released for conventional utilization. In this book the NS OTTO HAHN is described in detail and the experiences of operation as well as research and development activities are reported. All earlier publications of GKSS on the same subject are listed. (orig.) [de

Recent developments of the MOA thruster, a high performance plasma accelerator for nuclear power and propulsion applications

International Nuclear Information System (INIS)

Frischauf, N.; Hettmer, M.; Grassauer, A.; Bartusch, T.; Koudelka, O.

2008-01-01

More than 60 years after the late Nobel laureate Hannes Alfven had published a letter stating that oscillating magnetic fields can accelerate ionised matter via magneto-hydrodynamic interactions in a wave like fashion, the technical implementation of Alfven waves for propulsive purposes has been proposed, patented and examined for the first time by a group of inventors. The name of the concept, utilising Alfven waves to accelerate ionised matter for propulsive purposes, is MOA -Magnetic field Oscillating Amplified thruster. Alfven waves are generated by making use of two coils, one being permanently powered and serving also as magnetic nozzle, the other one being switched on and off in a cyclic way, deforming the field lines of the overall system. It is this deformation that generates Alfven waves, which are in the next step used to transport and compress the propulsive medium, in theory leading to a propulsion system with a much higher performance than any other electric propulsion system. Based on computer simulations, which were conducted to get a first estimate on the performance of the system, MOA is a highly flexible propulsion system, whose performance parameters might easily be adapted, by changing the mass flow and/or the power level. As such the system is capable to deliver a maximum specific impulse of 13116 s (12.87 mN) at a power level of 11.16 kW, using Xe as propellant, but can also be attuned to provide a thrust of 236.5 mN (2411 s) at 6.15 kW of power. While space propulsion is expected to be the prime application for MOA and is supported by numerous applications such as Solar and/or Nuclear Electric Propulsion or even as an 'afterburner system' for Nuclear Thermal Propulsion, other terrestrial applications can be thought of as well, making the system highly suited for a common space-terrestrial application research and utilization strategy. This paper presents the recent developments of the MOA Thruster R and D activities at QASAR, the company in

A review of the status of and prospects for nuclear marine propulsion

International Nuclear Information System (INIS)

Edwards, J.

1976-01-01

The review relates particularly to commercial nuclear merchant ships. The effects of the oil price escalation on world trade recession and price inflation are shown in relation to the rapid decrease in demand for new shipping and inflation in costs of any new construction. Economic analyses which began to be accepted as in favour of nuclear ships of relatively high power and high load factor have become somewhat less favourable, particularly from the point of view of higher investment costs and the presumed reluctance of shipowners to risk having these ships idle. On the other hand it is pointed out that the overall energy crisis remains and it is considered prudent to identify and seek solutions to those problems in nuclear ship propulsion which either still leave important uncertainties or which are likely to inhibit its use on a wide commercial scale. These are discussed under the following headings: economic assessments; safety acceptance and port entry; licensing and legislative problems; accidents and their consequences; decommissioning a nuclear ship; developments in the marine reactor designs. (U.K.)

Antimatter propulsion, status and prospects

Science.gov (United States)

Howe, Steven D.; Hynes, Michael V.

1986-01-01

The use of advanced propulsion techniques must be considered if the currently envisioned launch date of the manned Mars mission were delayed until 2020 or later. Within the next thirty years, technological advances may allow such methods as beaming power to the ship, inertial-confinement fusion, or mass-conversion of antiprotons to become feasible. A propulsion system with an ISP of around 5000 s would allow the currently envisioned mission module to fly to Mars in 3 months and would require about one million pounds to be assembled in Earth orbit. Of the possible methods to achieve this, the antiproton mass-conversion reaction offers the highest potential, the greatest problems, and the most fascination. Increasing the production rates of antiprotons is a high priority task at facilities around the world. The application of antiprotons to propulsion requires the coupling of the energy released in the mass-conversion reaction to thrust-producing mechanisms. Recent proposals entail using the antiprotons to produce inertial confinement fusion or to produce negative muons which can catalyze fusion. By increasing the energy released per antiproton, the effective cost, (dollars/joule) can be reduced. These proposals and other areas of research can be investigated now. These short term results will be important in assessing the long range feasibility of an antiproton powered engine.

Mars mission performance enhancement with hybrid nuclear propulsion

Energy Technology Data Exchange (ETDEWEB)

Dagle, J. E. [Pacific Northwest Lab., Richland, WA (United States); Noffsinger, K. E. [Pacific Northwest Lab., Richland, WA (United States); Segna, D. R. [USDOE Richland Operations Office, WA (United States)

1992-01-01

Nuclear electric propulsion (NEP), compared with chemical and nuclear thermal propulsion (NTP), can effectively deliver the same mass to Mars using much less propellant, consequently requiring less mass delivered to Earth orbit. The lower thrust of NEP requires a spiral trajectory near planetary bodies, which significantly increases the travel time. Although the total travel time is long, the portion of the flight time spent during interplanetary transfer is shorter, because the vehicle is thrusting for much longer periods of time. This has led to the supposition that NEP, although very attractive for cargo missions, is not suitable for piloted missions to Mars. However, with the application of a hybrid application of a hybrid approach to propulsion, the benefits of NEP can be utilized while drastically reducing the overall travel time required. Development of a dual-mode system, which utilizes high-thrust NTP to propel the spacecraft from the planetary gravitational influence and low-thrust NEP to accelerate in interplanetary space, eliminates the spiral trajectory and results in a much faster transit time than could be obtained by either NEP or NTP alone. This results in a mission profile with a lower initial mass in low Earth orbit. In addition, the propulsion system would have the capability to provide electrical power for mission applications.

Coordination and propulsion and non-propulsion phases in 100 meter breaststroke swimming.

Science.gov (United States)

Strzała, Marek; Krężałek, Piotr; Kucia-Czyszczoń, Katarzyna; Ostrowski, Andrzej; Stanula, Arkadiusz; Tyka, Anna K; Sagalara, Andrzej

2014-01-01

The main purpose of this study was to analyze the coordination, propulsion and non-propulsion phases in the 100 meter breaststroke race. Twenty-seven male swimmers (15.7 ± 1.98 years old) with the total body length (TBL) of 247.0 ± 10.60 [cm] performed an all-out 100 m breaststroke bout. The bouts were recorded with an underwater camera installed on a portable trolley. The swimming kinematic parameters, stroke rate (SR) and stroke length (SL), as well as the coordination indices based on propulsive or non-propulsive movement phases of the arms and legs were distinguished. Swimming speed (V100surface breast) was associated with SL (R = 0.41, p study were measured using partial correlations with controlled age. SL interplayed negatively with the limbs propulsive phase Overlap indicator (R = -0.46, p propulsion Glide indicator. The propulsion in-sweep (AP3) phase of arms and their non-propulsion partial air recovery (ARair) phase interplayed with V100surface breast (R = 0.51, p < 0.05 and 0.48 p < 0.05) respectively, displaying the importance of proper execution of this phase (AP3) and in reducing the resistance recovery phases in consecutive ones.

Pump-Fed, Compact, High Performance Green Propulsion System for Secondary Payloads, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Flight Works is proposing to expand its micropump-fed propulsion technology to the development of a low cost, compact, low tank pressure, high performance LPM-103S...

In-Space Demonstration of High Performance Green Propulsion and its Impact on Small Satellites

OpenAIRE

Anflo, Kjell; Crowe, Ben

2011-01-01

This paper summarizes the pre-launch activities and the results from the in-space demonstration of a novel propulsion system on the PRISMA main satellite, using a “Green” monopropellant. This propellant is a storable ADN-based monopropellant blend (i.e. LMP-103S). The basic mission for the High Performance Green Propulsion System (HPGP) has been successfully completed and all primary objectives of TRL 7 have been met. The HPGP technology is now flight proven and ready for implementation on fu...

Performance analyses of naval ships based on engineering level of simulation at the initial design stage

Directory of Open Access Journals (Sweden)

Dong-Hoon Jeong

2017-07-01

Full Text Available Naval ships are assigned many and varied missions. Their performance is critical for mission success, and depends on the specifications of the components. This is why performance analyses of naval ships are required at the initial design stage. Since the design and construction of naval ships take a very long time and incurs a huge cost, Modeling and Simulation (M & S is an effective method for performance analyses. Thus in this study, a simulation core is proposed to analyze the performance of naval ships considering their specifications. This simulation core can perform the engineering level of simulations, considering the mathematical models for naval ships, such as maneuvering equations and passive sonar equations. Also, the simulation models of the simulation core follow Discrete EVent system Specification (DEVS and Discrete Time System Specification (DTSS formalisms, so that simulations can progress over discrete events and discrete times. In addition, applying DEVS and DTSS formalisms makes the structure of simulation models flexible and reusable. To verify the applicability of this simulation core, such a simulation core was applied to simulations for the performance analyses of a submarine in an Anti-SUrface Warfare (ASUW mission. These simulations were composed of two scenarios. The first scenario of submarine diving carried out maneuvering performance analysis by analyzing the pitch angle variation and depth variation of the submarine over time. The second scenario of submarine detection carried out detection performance analysis by analyzing how well the sonar of the submarine resolves adjacent targets. The results of these simulations ensure that the simulation core of this study could be applied to the performance analyses of naval ships considering their specifications.

Development of NESSY (Nuclear ship Engineering Simulation SYstem) and its application to dynamic analysis

International Nuclear Information System (INIS)

Kusunoki, T.; Uematsu, H.; Kobayashi, H.

1992-01-01

A marine reactor plant sustains incessant load change and the effects of vibration and ship motions due to the maneuvering and dynamic conditions in the marine environment. The change of process variables of the reactor plant is made in accordance with the load change and other effects, and also results in the propeller revolution change and subsequently affects on ship motions. In order to grasp dynamic behavior of the reactor plant in normal operation, including port entry and departure, and also in abnormal conditions such as anticipated transient and accidents, the Nuclear ship Engineering Simulation SYstem (simply ENSSY, hereinafter) carriers out combined analysis in which the behaviors of the ship propulsion, the reactor plant and the secondary systems are simultaneously calculated in each time step. (author)

Contribution to the use of a solid moderator gas reactor, for naval propulsion

International Nuclear Information System (INIS)

Pheline, J.; Gautier, A.

1960-01-01

In this contribution, the authors discuss works performed in France for the development of nuclear propulsion in merchant ships, notably for an oil tanker of 50.000 tons with 17 knot speed, i.e. a 20.000 Hp engine with an energy produced by a 60 MW gas reactor with a solid moderator and comprising 400 channels loaded with uranium oxide enriched ay 2.8 per cent and sheathed with a refractory alloy. The authors discuss the possible materials for the moderator, the heat transfer medium, the sheath, the fuel and the structures, and report technological studies (mechanical tests, irradiation tests) performed to investigate material properties and their behaviour in operation conditions. They report tests performed to investigate core structure characteristics with respect to neutrons. They finally briefly present a prototype

Development and construction of an HTS rotor for ship propulsion application

Energy Technology Data Exchange (ETDEWEB)

Nick, W; Frank, M; Kummeth, P; Rabbers, J J; Wilke, M; Schleicher, K, E-mail: wolfgang.nick@siemens.co [Siemens AG, CT PS 3, Guenther-Scharowsky-Str. 1, D-91050 Erlangen (Germany)

2010-06-01

A low-speed high-torque HTS machine is being developed at Siemens on the basis of previous steps (400kW demonstrator, 4MVA generator). The goal of the programme is to utilize the characteristic advantages offered by electrical machines with HTS-excited rotor, such as efficiency, compact size, and dynamic performance. To be able to address future markets, requirements from ship classification as well as potential customers have to be met. Electromagnetic design cannot be focused on nominal operation only, but has to deal with failure modes like short circuit too. Utilization of superconductor requires to consider margins taking into account that the windings have to operate reliably not only in 'clean' laboratory conditions, but in rough environment with the stator connected to a power converter. Extensive quality control is needed to ensure homogenous performance (current capacity, electrical insulation, dimensions) for the large quantity of HTS (45 km). The next step was to set up and operate a small-scale 'industrial' manufacturing process to produce HTS windings in a reproducible way, including tests at operating conditions. A HTS rotor includes many more components compared to a conventional one, so tough geometric tolerances must be met to ensure robust performance of the system. All this gives a challenging task, which will be concluded by cold testing of the rotor in a test facility. Then the rotor will be delivered for assembly to the stator. In following machine tests the performance of the innovative HTS drive system will be demonstrated.

Evaluation and comparison of electric propulsion motors for submarines

OpenAIRE

Harbour, Joel P.

2001-01-01

CIVINS (Civilian Institutions) Thesis document The Navy has announced its conviction to make its warships run on electric power through the decision to make its newest line of destroyers propelled with an electric propulsion system. Several ship construction firms and electric motor manufacturers are thus striving to develop enabling technology, including high power density motors. The purpose of this thesis is to evaluate some of the proposed motor designs for use in a submarine. Permanen...

Advanced Chemical Propulsion Study

Science.gov (United States)

Woodcock, Gordon; Byers, Dave; Alexander, Leslie A.; Krebsbach, Al

2004-01-01

A study was performed of advanced chemical propulsion technology application to space science (Code S) missions. The purpose was to begin the process of selecting chemical propulsion technology advancement activities that would provide greatest benefits to Code S missions. Several missions were selected from Code S planning data, and a range of advanced chemical propulsion options was analyzed to assess capabilities and benefits re these missions. Selected beneficial applications were found for higher-performing bipropellants, gelled propellants, and cryogenic propellants. Technology advancement recommendations included cryocoolers and small turbopump engines for cryogenic propellants; space storable propellants such as LOX-hydrazine; and advanced monopropellants. It was noted that fluorine-bearing oxidizers offer performance gains over more benign oxidizers. Potential benefits were observed for gelled propellants that could be allowed to freeze, then thawed for use.

Critical Propulsion Components. Volume 1; Summary, Introduction, and Propulsion Systems Studies

Science.gov (United States)

2005-01-01

Several studies have concluded that a supersonic aircraft, if environmentally acceptable and economically viable, could successfully compete in the 21st century marketplace. However, before industry can commit to what is estimated as a 15 to 20 billion dollar investment, several barrier issues must be resolved. In an effort to address these barrier issues, NASA and Industry teamed to form the High-Speed Research (HSR) program. As part of this program, the Critical Propulsion Components (CPC) element was created and assigned the task of developing those propulsion component technologies necessary to: (1) reduce cruise emissions by a factor of 10 and (2) meet the ever-increasing airport noise restrictions with an economically viable propulsion system. The CPC-identified critical components were ultra-low emission combustors, low-noise/high-performance exhaust nozzles, low-noise fans, and stable/high-performance inlets. Propulsion cycle studies (coordinated with NASA Langley Research Center sponsored airplane studies) were conducted throughout this CPC program to help evaluate candidate components and select the best concepts for the more complex and larger scale research efforts. The propulsion cycle and components ultimately selected were a mixed-flow turbofan (MFTF) engine employing a lean, premixed, prevaporized (LPP) combustor coupled to a two-dimensional mixed compression inlet and a two-dimensional mixer/ejector nozzle. Due to the large amount of material presented in this report, it was prepared in four volumes; Volume 1: Summary, Introduction, and Propulsion System Studies, Volume 2: Combustor, Volume 3: Exhaust Nozzle, and Volume 4: Inlet and Fan/ Inlet Acoustic Team.

A 20 MW podded ship underwater electromagnetic signature - the alternative electric field; Signature electromagnetique sous-marine d'un paquebot de 20 MW a pods - le champ electrique alternatif

Energy Technology Data Exchange (ETDEWEB)

Lucas, B.; Henocq, H.; Rannou, C. [Delegation Generale pour l' Armement, DET/GESMA, 75 - Paris (France); Albert, Th.; Harpin, D. [ALSTOM Marine (France); Bourguet, S.; Guerin, P. [Institut de Recherche en Electrotechnique et Electronique de Nantes Atlantique, 44 (France)

2006-03-15

Today, electric podded propulsion is used for many ships, cruise liners and Navy vessels.This propulsion uses high currents in extremely low frequencies (ELFE); currents flow through electrical network, equipment and pods. These alternative currents could generate important underwater electromagnetic field. GESMA has to quantify the level of this field and its impact on the signature of this kind of ship. Then, GESMA carried out electromagnetic measurements using a multi-sensors underwater and autonomous facility named AMI. It was placed on the route of a 20 MW podded ship, at one hundred meters depth from the surface. Especially, AMI observed an alternative radiated electric field... (authors)

Performance of catalysts for CO removal by methanation

Energy Technology Data Exchange (ETDEWEB)

Oshiro, Hitoshi; Nagaya, Kiichi; Mitani, Koichi [Hitachi Zosen Corp., Osaka (Japan)

1996-12-31

This report forms part of a joint study on a PEFC propulsion system for surface ships, summarized in a presentation to this Seminar, entitled {open_quotes}Study on a Polymer Electrolyte Fuel Cell (PEFC) Propulsion System for Surface Ships{close_quotes}, and which envisages application to a 1,500 DWT cargo vessel. The aspect treated here concerns an experiment in reducing by methanation to a level below 10 ppm the CO that is contained to around 1% in reformate gas.

Distributed Propulsion Vehicles

Science.gov (United States)

Kim, Hyun Dae

2010-01-01

Since the introduction of large jet-powered transport aircraft, the majority of these vehicles have been designed by placing thrust-generating engines either under the wings or on the fuselage to minimize aerodynamic interactions on the vehicle operation. However, advances in computational and experimental tools along with new technologies in materials, structures, and aircraft controls, etc. are enabling a high degree of integration of the airframe and propulsion system in aircraft design. The National Aeronautics and Space Administration (NASA) has been investigating a number of revolutionary distributed propulsion vehicle concepts to increase aircraft performance. The concept of distributed propulsion is to fully integrate a propulsion system within an airframe such that the aircraft takes full synergistic benefits of coupling of airframe aerodynamics and the propulsion thrust stream by distributing thrust using many propulsors on the airframe. Some of the concepts are based on the use of distributed jet flaps, distributed small multiple engines, gas-driven multi-fans, mechanically driven multifans, cross-flow fans, and electric fans driven by turboelectric generators. This paper describes some early concepts of the distributed propulsion vehicles and the current turboelectric distributed propulsion (TeDP) vehicle concepts being studied under the NASA s Subsonic Fixed Wing (SFW) Project to drastically reduce aircraft-related fuel burn, emissions, and noise by the year 2030 to 2035.

Some Thoughts About Water Analysis in Shipboard Steam Propulsion Systems for Marine Engineering Students.

Science.gov (United States)

Schlenker, Richard M.; And Others

Information is presented about the problems involved in using sea water in the steam propulsion systems of large, modern ships. Discussions supply background chemical information concerning the problems of corrosion, scale buildup, and sludge production. Suggestions are given for ways to maintain a good water treatment program to effectively deal…

Chemistry and propulsion; Chimie et propulsions

Energy Technology Data Exchange (ETDEWEB)

Potier, P [Maison de la Chimie, 75 - Paris (France); Davenas, A [societe Nationale des Poudres et des Explosifs - SNPE (France); Berman, M [Air Force Office of Scientific Research, Arlington, VA (United States); and others

2002-07-01

During the colloquium on chemistry and propulsion, held in march 2002, ten papers have been presented. The proceedings are brought in this document: ramjet, scram-jet and Pulse Detonation Engine; researches and applications on energetic materials and propulsion; advances in poly-nitrogen chemistry; evolution of space propulsion; environmental and technological stakes of aeronautic propulsion; ramjet engines and pulse detonation engines, automobiles thermal engines for 2015, high temperature fuel cells for the propulsion domain, the hydrogen and the fuel cells in the future transports. (A.L.B.)

Analysis of Engine Propeller Matching of DC Motor as a Main Propulsion

Directory of Open Access Journals (Sweden)

Eddy Setyo Koenhardono

2017-12-01

Full Text Available The development of ship always searches through the most benefits system for reducing costs of propulsion system without increase pollution. Diesel propulsion system or also known as conventional propulsion system is efficient but requires high operating costs and increase high level of marine pollution. Electrical propulsion system is using electric motors as the prime mover of the propeller. There are 2 types of electric motors that will be used for research of electric propulsion system, there are; DC motors and three-phases induction motor. As the use of DC motor as a prime mover for this electrical propulsion system, this study determines the characteristic between voltage terminal with torque and also field current with torque. It results that torque produced by the DC motor is in the same magnitude with the speed (RPM. The higher the speed have shaped the value of the torque. The input and terminal voltages adjusts all variables and results. In this study, different field voltage creates different pattern of motor envelope. Its manner to propeller curve occurs total different results. With field voltage of 50 V, the ranges of motor envelope immoveable in the point of 150% of present speed and 160%. While field voltage of 60 V serves larger ranges of motor envelope which possible to reach further than 50 V curve.

A numerical study on ship-ship interaction in shallow and restricted waterway

Directory of Open Access Journals (Sweden)

Sungwook Lee

2015-09-01

Full Text Available In the present study, a numerical prediction method on the hydrodynamic interaction force and moment between two ships in shallow and restricted waterway is presented. Especially, the present study proposes a methodology to overcome the limitation of the two dimensional perturbation method which is related to the moored-passing ship interaction. The validation study was performed and compared with the experiment, firstly. Afterward, in order to propose a methodology in terms with the moored-passing ship interaction, further studies were performed for the moored-passing ship case with a Reynolds Averaged Navier-Stokes (RANS calculation which is using OpenFOAM with Arbitrary Coupled Mesh Interface (ACMI technique and compared with the experiment result. Finally, the present study proposes a guide to apply the two dimensional perturbation method to the moored-passing ship interaction. In addition, it presents a possibility that the RANS calculation with ACMI can applied to the ship-ship interaction without using a overset moving grid technique.

Centralized versus distributed propulsion

Science.gov (United States)

Clark, J. P.

1982-01-01

The functions and requirements of auxiliary propulsion systems are reviewed. None of the three major tasks (attitude control, stationkeeping, and shape control) can be performed by a collection of thrusters at a single central location. If a centralized system is defined as a collection of separated clusters, made up of the minimum number of propulsion units, then such a system can provide attitude control and stationkeeping for most vehicles. A distributed propulsion system is characterized by more numerous propulsion units in a regularly distributed arrangement. Various proposed large space systems are reviewed and it is concluded that centralized auxiliary propulsion is best suited to vehicles with a relatively rigid core. These vehicles may carry a number of flexible or movable appendages. A second group, consisting of one or more large flexible flat plates, may need distributed propulsion for shape control. There is a third group, consisting of vehicles built up from multiple shuttle launches, which may be forced into a distributed system because of the need to add additional propulsion units as the vehicles grow. The effects of distributed propulsion on a beam-like structure were examined. The deflection of the structure under both translational and rotational thrusts is shown as a function of the number of equally spaced thrusters. When two thrusters only are used it is shown that location is an important parameter. The possibility of using distributed propulsion to achieve minimum overall system weight is also examined. Finally, an examination of the active damping by distributed propulsion is described.

Commercially-driven human interplanetary propulsion systems: Rationale, concept, technology, and performance requirements

International Nuclear Information System (INIS)

Williams, C.H.; Borowski, S.K.

1996-01-01

Previous studies of human interplanetary missions are largely characterized by long trip times, limited performance capabilities, and enormous costs. Until these missions become dramatically more open-quote open-quote commercial-friendly close-quote close-quote, their funding source and rationale will be restricted to national governments and their political/scientific interests respectively. A rationale is discussed for human interplanetary space exploration predicated on the private sector. Space propulsion system requirements are identified for interplanetary transfer times of no more than a few weeks/months to and between the major outer planets. Nuclear fusion is identified as the minimum requisite space propulsion technology. A conceptual design is described and evolutionary catalyzed-DD to DHe 3 fuel cycles are proposed. Magnetic nozzles for direct thrust generation and quantifying the operational aspects of the energy exchange mechanisms between high energy reaction products and neutral propellants are identified as two of the many key supporting technologies essential to satisfying system performance requirements. Government support of focused, breakthrough technologies is recommended at funding levels appropriate to other ongoing federal research. copyright 1996 American Institute of Physics

Propulsion System and Orbit Maneuver Integration in CubeSats: Trajectory Control Strategies Using Micro Ion Propulsion

Science.gov (United States)

Hudson, Jennifer; Martinez, Andres; Petro, Andrew

2015-01-01

The Propulsion System and Orbit Maneuver Integration in CubeSats project aims to solve the challenges of integrating a micro electric propulsion system on a CubeSat in order to perform orbital maneuvers and control attitude. This represents a fundamentally new capability for CubeSats, which typically do not contain propulsion systems and cannot maneuver far beyond their initial orbits.

The Nuclear Cryogenic Propulsion Stage

Science.gov (United States)

Houts, Michael G.; Kim, Tony; Emrich, William J.; Hickman, Robert R.; Broadway, Jeramie W.; Gerrish, Harold P.; Doughty, Glen; Belvin, Anthony; Borowski, Stanley K.; Scott, John

2014-01-01

The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progress made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP). Nuclear propulsion can be affordable and viable compared to other propulsion systems and must overcome a biased public fear due to hyper-environmentalism and a false perception of radiation and explosion risk.

9975 Shipping Package Performance Of Alternate Materials For Long-Term Storage Application

International Nuclear Information System (INIS)

Skidmore, E.; Hoffman, E.; Daugherty, W.

2010-01-01

The Model 9975 shipping package specifies the materials of construction for its various components. With the loss of availability of material for two components (cane fiberboard overpack and Viton(reg s ign) GLT O-rings), alternate materials of construction were identified and approved for use for transport (softwood fiberboard and Viton(reg s ign) GLT-S O-rings). As these shipping packages are part of a long-term storage configuration at the Savannah River Site, additional testing is in progress to verify satisfactory long-term performance of the alternate materials under storage conditions. The test results to date can be compared to comparable results on the original materials of construction to draw preliminary conclusions on the performance of the replacement materials.

Residual Generation for the Ship Benchmark Using Structural Approach

DEFF Research Database (Denmark)

Cocquempot, V.; Izadi-Zamanabadi, Roozbeh; Staroswiecki, M

1998-01-01

The prime objective of Fault-tolerant Control (FTC) systems is to handle faults and discrepancies using appropriate accommodation policies. The issue of obtaining information about various parameters and signals, which have to be monitored for fault detection purposes, becomes a rigorous task...... with the growing number of subsystems. The structural approach, presented in this paper, constitutes a general framework for providing information when the system becomes complex. The methodology of this approach is illustrated on the ship propulsion benchmark....

Fluid Distribution Analysis of Kite Sail for Application on Ship

Directory of Open Access Journals (Sweden)

. Amiadji

2017-09-01

Full Text Available The increasing number of operating ships resulted in high air pollution from the combustion of the ship's engine. Efforts to utilize alternative energy to reduce ship engine work have been done, one of them is using unlimited alternative energy that is wind where one of its application of is the application of new ships sail, kite sail as auxiliary system of ship propulsion . In this final project purposed to find out the value of aerodynamic force of kite sail and power it can generated , with a CFD method that uses 3 kite sail design forms, rectangular, triangular, and elliptical, with an area of 160 m2 this models are simulated at wind speed variations from 13.4 m / s up 15.82 m / s and angel of attack variation of 15.20, and 25. From the variation obtained the total aerodynamic force generated can reach 28.73 kN in rectangular shape, 30.79 kN of Elipsical shape, and 27.55 kN of triangular shape, on variant Angel Of attack 25. From the value of the aerodynamic force, each kite sail capable of generating power, on a rectangular kite sail of up to 263.02 kW, an elipsical 276.75 kW, and a triangular 252.63 kW.

Research on applications of rectangular beam in micro laser propulsion

International Nuclear Information System (INIS)

Jiao, L.; Cai, J.; Ma, H.H.; Li, G.X.; Li, L.; Shen, Z.W.; Tang, Z.P.

2014-01-01

Highlights: • Diode laser bar of 808 nm is introduced into the micro laser propulsion field. • Double base propellant (DBP) coating with BOPP substrate was obtained. • The combination of laser power and energy decides the propulsion performance. • The new rectangular beam prefers to produce higher impulse. - Abstract: Micro laser propulsion is a new technology with brilliant future. In order to reduce the thruster mass and volume further, laser bar is introduced into the micro laser propulsion field. A new kind of 220 × 20 μm rectangular beam of 808 nm was obtained by oval lens compressing the light of diode at fast axes and slow axes. The effect of laser power, energy and coating thickness of double base propellant on propulsion performance was studied. Propulsion performance of double base propellant under static and dynamic mode shows some different characters. Compared to round beam, the new beam prefers to produce higher impulse. Ablation efficiency of DBP shows better performance in short laser duration. The combination of power density and energy density decides the laser propulsion performance. The new rectangular beam is appropriate for millisecond micro-laser propulsion

NASA's Nuclear Thermal Propulsion Project

Science.gov (United States)

Houts, Michael G.; Mitchell, Doyce P.; Kim, Tony; Emrich, William J.; Hickman, Robert R.; Gerrish, Harold P.; Doughty, Glen; Belvin, Anthony; Clement, Steven; Borowski, Stanley K.;

Blowin' in the wind? Drivers and barriers for the uptake of wind propulsion in international shipping

NARCIS (Netherlands)

Rojon, I.; Dieperink, C.

2014-01-01

International shipping transports around 90% of global commerce and is of major importance for the global economy. Whilst it is the most efficient and environmentally friendly mode of transport, CO2 emissions from shipping activities still account for an estimated 3% of global emissions. One means

The KiteShip (TM) project

Energy Technology Data Exchange (ETDEWEB)

De winter, Francis; Swenson, Ronald B; Culp, David [Santa Cruz, CA (United States)

2000-07-01

Foreseeable crude oil shortages provide an incentive to use wind power in the merchant marine again, to save fuel by providing propulsion power. Out prototype KiteShip (TM), a lightweight fiberglass proa 7 m long, has been sailed with 2 different sizes of kites in fresh water. The kites are shaped like parafoil wings, with areas of 4 sq m and 9 sq m. Steering is accomplished with two coupled rudders, one fore and one aft. We have been encouraged by the boat speed and the handling, although we have encountered only light winds up to now, of no more than about 20 km/ht. In the next phase we will employ a custom-built kite of 2 sq m. and will also start sailing in the ocean with heavier winds, of 40 km/hr and above. [Spanish] La escasez previsible de petroleo motiva volver a utilizar la fuerza del viento en la marina mercante, para ahorrar combustible al suministrar la potencia de propulsion. Nuestro prototipo KiteShip (MR), con una proa ligera de fibra de vidrio con 7 m de longitud, ha navegado con dos diferentes tipos de vela ({sup k}ite{sup )} en agua dulce. Los kites tienen forma de alas de parafol, con areas de 4 m{sup 2} y 9 m{sup 2}. La direccion se logra con dos timones acoplados, uno en la proa y otro en la popa. Nos entusiasmo la velocidad del bote y su manejo, aunque hemos encontrado hasta ahora solo vientos ligeros de no mas de alrededor de 20 km/hr. En la siguiente fase emplearemos un kite hecho a la medida, de 28 m{sup 2} y tambien comenzaremos a navegar en el oceano con vientos mas fuertes de 40 km/hr o mas.

Monofilament Vaporization Propulsion (MVP) System, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Monofilament Vaporization Propulsion (MVP) is a new propulsion technology targeted at secondary payload applications. It does not compromise on performance while...

An Overview of Cube-Satellite Propulsion Technologies and Trends

Directory of Open Access Journals (Sweden)

Akshay Reddy Tummala

2017-12-01

Full Text Available CubeSats provide a cost effective means to perform scientific and technological studies in space. Due to their affordability, CubeSat technologies have been diversely studied and developed by educational institutions, companies and space organizations all over the world. The CubeSat technology that is surveyed in this paper is the propulsion system. A propulsion system is the primary mobility device of a spacecraft and helps with orbit modifications and attitude control. This paper provides an overview of micro-propulsion technologies that have been developed or are currently being developed for CubeSats. Some of the micro-propulsion technologies listed have also flown as secondary propulsion systems on larger spacecraft. Operating principles and key design considerations for each class of propulsion system are outlined. Finally, the performance factors of micro-propulsion systems have been summarized in terms of: first, a comparison of thrust and specific impulse for all propulsion systems; second, a comparison of power and specific impulse, as also thrust-to-power ratio and specific impulse for electric propulsion systems.

Enabling Electric Propulsion for Flight

Science.gov (United States)

Ginn, Starr Renee

2015-01-01

Team Seedling project AFRC and LaRC 31ft distributed electric propulsion wing on truck bed up 75 miles per hour for coefficient of lift validation. Convergent Aeronautic Solutions project, sub-project Convergent Electric Propulsion Technologies AFRC, LaRC and GRC, re-winging a 4 passenger Tecnam aircraft with a 31ft distributed electric propulsion wing. Advanced Air Transport Technologies (Fixed Wing), Hybrid Electric Research Theme, developing a series hybrid ironbird and flight sim to study integration and performance challenges in preparation for a 1-2 MW flight project.

Seabed Protection Systems to prevent Scour from High-Speed Ships

OpenAIRE

Evans, G

2010-01-01

This document reviews the scour protection systems required around port structures where these are to be used for the berthing of vessels powered by water jet systems. The development of a scour protection system at Poole Harbour in Dorset has been documented and reviewed and a series of laboratory investigations were then undertaken. This has enabled a greater understanding of the scour mechanisms from the water jet propulsion systems of High Speed Ships. This work has shown t...

Ships on the sea are responsible for enormous emissions. A sea journey which is sooty...; Schiffe auf dem Meer sind fuer gewaltige Emissionen verantwortlich. Eine Seefahrt, die ist russig...

Energy Technology Data Exchange (ETDEWEB)

Muehleisen, Martin

2012-03-15

Since the conversion from sailing ships to steamships at the end of the 18th century, ships emit large amounts of sulfur, nitrogen oxides and soot into the air. Environment, passengers and residents of port cities constantly are exposed to health hazards. The conversion to environmentally friendly propulsion technology at the maritime shipping as well as the inland waterway transport is a tough process.

Effects of Seated Postural Stability and Trunk and Upper Extremity Strength on Performance during Manual Wheelchair Propulsion Tests in Individuals with Spinal Cord Injury: An Exploratory Study.

Science.gov (United States)

Gagnon, Dany H; Roy, Audrey; Gabison, Sharon; Duclos, Cyril; Verrier, Molly C; Nadeau, Sylvie

2016-01-01

Objectives. To quantify the association between performance-based manual wheelchair propulsion tests (20 m propulsion test, slalom test, and 6 min propulsion test), trunk and upper extremity (U/E) strength, and seated reaching capability and to establish which ones of these variables best predict performance at these tests. Methods. 15 individuals with a spinal cord injury (SCI) performed the three wheelchair propulsion tests prior to discharge from inpatient SCI rehabilitation. Trunk and U/E strength and seated reaching capability with unilateral hand support were also measured. Bivariate correlation and multiple linear regression analyses allowed determining the best determinants and predictors, respectively. Results. The performance at the three tests was moderately or strongly correlated with anterior and lateral flexion trunk strength, anterior seated reaching distance, and the shoulder, elbow, and handgrip strength measures. Shoulder adductor strength-weakest side explained 53% of the variance on the 20-meter propulsion test-maximum velocity. Shoulder adductor strength-strongest side and forward seated reaching distance explained 71% of the variance on the slalom test. Handgrip strength explained 52% of the variance on the 6-minute propulsion test. Conclusion. Performance at the manual wheelchair propulsion tests is explained by a combination of factors that should be considered in rehabilitation.

An Overview of Brazilian Developments in Beamed Energy Aerospace Propulsion and Vehicle Performance Control

International Nuclear Information System (INIS)

Minucci, M. A. S.

2008-01-01

Beamed energy propulsion and beamed energy vehicle performance control concepts are equally promising and challenging. In Brazil, the two concepts are being currently investigated at the Prof Henry T Nagamatsu Laboratory of Aerothermodynamics and Hypersonics, of the Institute for Advanced Studies--IEAv, in collaboration with the Rensselaer Polytechnic Institute--RPI, Troy, NY, and the United States Air force Research Laboratory-AFRL. Until recently, only laser energy addition for hypersonic flow control was being investigated at the Laboratory using a 0.3 m nozzle exit diameter hypersonic shock tunnel, T2, and two 7 joule CO 2 TEA lasers. Flow visualization, model pressure and heat flux measurements of the laser energy addition perturbed flow around a model were produced as a result of this joint IEAv-RPI investigation. Presently, with the participation of AFRL and the newly commissioned 0.6 m. nozzle exit diameter hypersonic shock tunnel, T3, a more ambitious project is underway. Two 400 Joule Lumonics 620 CO 2 TEA lasers will deliver a 20 cm X 25 cm propulsive laser beam to a complete laser propelled air breather/rocket hypersonic engine, located inside T3 test section. Schlieren photographs of the flow inside de engine as well as surface and heat flux measurements will be performed for free stream Mach numbers ranging from 6 to 25. The present paper discusses past, present and future Brazilian activities on beamed energy propulsion and related technologies

Proposal of C-core Type Transverse Flux Motor for Ship Propulsion – Increasing Torque Density by Dense Stator Configuration –

Directory of Open Access Journals (Sweden)

Y. Yamamoto

2014-02-01

Full Text Available Electric ship propulsion system has been drawing attention as a solution for savings in energy and maintenance costs. The system is mainly composed of motor, converter and gearbox and required for high torque at low speed. In this situation, transverse flux motors (TFMs have been proposed to fulfill the low-speed high-torque characteristic due to suitable for short pole pitch and large number of poles to increase torque output. In this trend, we have proposed C-core type motors taking advantage of TFMs’ structure. In this manuscript, a simple design method based on the magnetic-circuit theory and simple modeling of the motor is proposed to search a design parameter for maximizing torque as a pre-process of numerical study. The method takes into consideration the effects of magnetic leakage flux, magnetic saturation and pole-core combination in accordance with the systematic theory. The simple modeling is conducted based on a dense armature structure in previous axial flux motors (AFMs applied to the new motor design. The validity of the method is verified by 3-D finite element analysis (FEA and relative error is at most 20%. The minimalist design is shown to be advantageous for effective use in 3-D FEA. As a detailed design by the FEA, high torque density and low cogging to output ratio can be achieved simultaneously in the proposed machine.

Wheelchairs propulsion analysis: review

Directory of Open Access Journals (Sweden)

Yoshimasa Sagawa Júnior

Full Text Available OBJECTIVES: To analyze aspects related with wheelchair propulsion. MATERIALS AND METHODS: In order to delineate this review the search for information was carried out within electronics databases, using the following descriptors: "wheelchair propulsion", "wheelchair biomechanics" e "wheelchair users". Full papers published in English and French were included in the study. RESULTS: The wheelchair propulsion is a complex movement that requires the execution of repeated bi manual forces applications during a short time period. In this movement high levels of force must be produced due to the bad mechanical performance of the wheelchair. Could be characterized that wheelchair users are not satisfied with their wheelchair, the places are not adapted to their presence and lack of specific criteria for the adjustment of this equipment. The main points to look at are the seat height in relation to elbow flexion (100-120 degrees with his hand in the propulsion rim and tire pressure. The semicircular mode of technique propulsion seems to be more appropriate; in this pattern the wheelchair user returns his hand under the rim after propulsion. Efforts in wheelchairs are high and the incidence of injuries in wheelchair users is high. CONCLUSION: One can conclude that in spite of researchers’ efforts there are still many divergences between topics and methods of evaluation, what makes difficult to apply the experimental results to the wheelchairs users’ daily life.

Materials Advance Chemical Propulsion Technology

Science.gov (United States)

2012-01-01

In the future, the Planetary Science Division of NASA's Science Mission Directorate hopes to use better-performing and lower-cost propulsion systems to send rovers, probes, and observers to places like Mars, Jupiter, and Saturn. For such purposes, a new propulsion technology called the Advanced Materials Bipropellant Rocket (AMBR) was developed under NASA's In-Space Propulsion Technology (ISPT) project, located at Glenn Research Center. As an advanced chemical propulsion system, AMBR uses nitrogen tetroxide oxidizer and hydrazine fuel to propel a spacecraft. Based on current research and development efforts, the technology shows great promise for increasing engine operation and engine lifespan, as well as lowering manufacturing costs. In developing AMBR, ISPT has several goals: to decrease the time it takes for a spacecraft to travel to its destination, reduce the cost of making the propulsion system, and lessen the weight of the propulsion system. If goals like these are met, it could result in greater capabilities for in-space science investigations. For example, if the amount (and weight) of propellant required on a spacecraft is reduced, more scientific instruments (and weight) could be added to the spacecraft. To achieve AMBR s maximum potential performance, the engine needed to be capable of operating at extremely high temperatures and pressure. To this end, ISPT required engine chambers made of iridium-coated rhenium (strong, high-temperature metallic elements) that allowed operation at temperatures close to 4,000 F. In addition, ISPT needed an advanced manufacturing technique for better coating methods to increase the strength of the engine chamber without increasing the costs of fabricating the chamber.

An Airbreathing Launch Vehicle Design with Turbine-Based Low-Speed Propulsion and Dual Mode Scramjet High-Speed Propulsion

Science.gov (United States)

Moses, P. L.; Bouchard, K. A.; Vause, R. F.; Pinckney, S. Z.; Ferlemann, S. M.; Leonard, C. P.; Taylor, L. W., III; Robinson, J. S.; Martin, J. G.; Petley, D. H.

1999-01-01

Airbreathing launch vehicles continue to be a subject of great interest in the space access community. In particular, horizontal takeoff and horizontal landing vehicles are attractive with their airplane-like benefits and flexibility for future space launch requirements. The most promising of these concepts involve airframe integrated propulsion systems, in which the external undersurface of the vehicle forms part of the propulsion flowpath. Combining of airframe and engine functions in this manner involves all of the design disciplines interacting at once. Design and optimization of these configurations is a most difficult activity, requiring a multi-discipline process to analytically resolve the numerous interactions among the design variables. This paper describes the design and optimization of one configuration in this vehicle class, a lifting body with turbine-based low-speed propulsion. The integration of propulsion and airframe, both from an aero-propulsive and mechanical perspective are addressed. This paper primarily focuses on the design details of the preferred configuration and the analyses performed to assess its performance. The integration of both low-speed and high-speed propulsion is covered. Structural and mechanical designs are described along with materials and technologies used. Propellant and systems packaging are shown and the mission-sized vehicle weights are disclosed.

Advanced Demonstration of Motion Correction for Ship-to-Ship Passive Inspections

Energy Technology Data Exchange (ETDEWEB)

Ziock, Klaus-Peter [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Boehnen, Chris Bensing [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ernst, Joseph [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2013-09-30

Passive radiation detection is a key tool for detecting illicit nuclear materials. In maritime applications it is most effective against small vessels where attenuation is of less concern. Passive imaging provides: discrimination between localized (threat) and distributed (non-threat) sources, removal of background fluctuations due to nearby shorelines and structures, source localization to an individual craft in crowded waters, and background subtracted spectra. Unfortunately, imaging methods cannot be easily applied in ship-to-ship inspections because relative motion of the vessels blurs the results over many pixels, significantly reducing sensitivity. This is particularly true for the smaller water craft where passive inspections are most valuable. In this project we performed tests and improved the performance of an instrument (developed earlier under, “Motion Correction for Ship-to-Ship Passive Inspections”) that uses automated tracking of a target vessel in visible-light images to generate a 3D radiation map of the target vessel from data obtained using a gamma-ray imager.

Basic Study of Superconductive Actuator

OpenAIRE

涌井, 和也; 荻原, 宏康

2000-01-01

There are two kinds of electromagnetic propulsion ships : a superconductive electromagnetic propulsion ship and a superconductive electricity propulsion ship. A superconductive electromagnetic propulsion ship uses the electromagnetic force (Lorenz force) by the interaction between a magnetic field and a electric current. On the other hand, a superconductive electricity propulsion ship uses screws driven by a superconductive motor. A superconductive propulsion ship technique has the merits of ...

Nuclear thermal propulsion engine cost trade studies

International Nuclear Information System (INIS)

Paschall, R.K.

1993-01-01

The NASA transportation strategy for the Mars Exploration architecture includes the use of nuclear thermal propulsion as the primary propulsion system for Mars transits. It is anticipated that the outgrowth of the NERVA/ROVER programs will be a nuclear thermal propulsion (NTP) system capable of providing the propulsion for missions to Mars. The specific impulse (Isp) for such a system is expected to be in the 870 s range. Trade studies were conducted to investigate whether or not it may be cost effective to invest in a higher performance (Isp>870 s) engine for nuclear thermal propulsion for missions to Mars. The basic cost trades revolved around the amount of mass that must be transported to low-earth orbit prior to each Mars flight and the cost to launch that mass. The mass required depended on the assumptions made for Mars missions scenarios including piloted/cargo flights, number of Mars missions, and transit time to Mars. Cost parameters included launch cost, program schedule for development and operations, and net discount rate. The results were very dependent on the assumptions that were made. Under some assumptions, higher performance engines showed cost savings in the billions of dollars; under other assumptions, the additional cost to develop higher performance engines was not justified

Development of the nuclear ship MUTSU spent fuel shipping cask

International Nuclear Information System (INIS)

Ishizuka, M.; Umeda, M.; Nawata, Y.; Sato, H.; Honami, M.; Nomura, T.; Ohashi, M.; Higashino, A.

1989-01-01

After the planned trial voyage (4700 MWD/MTU) of the nuclear ship MUTSU in 1990, her spent fuel assemblies, initially made of two types of enriched UO 2 (3.2wt% and 4.4wt%), will be transferred to the reprocessing plant soon after cooling down in the ship reactor for more than one year. For transportation, the MUTSU spent fuel shipping casks will be used. Prior to transportation to the reprocessing plant, the cooled spent fuel assemblies will be removed from the reactor to the shipping casks and housed at the spent fuel storage facility on site. In designing the MUTSU spent fuel shipping cask, considerations were given to make the leak-tightness and integrity of the cask confirmable during storage. The development of the cask and the storage function demonstration test were performed by Japan Atomic Energy Research Institute (JAERI) and Mitsubishi Heavy Industries, Ltd. (MHI). One prototype cask for the storage demonstration test and licensed thirty-five casks were manufactured between 1987 and 1988

Simulation research on operation scheme of dissymmetrical main engine of CODOG propulsion system

Directory of Open Access Journals (Sweden)

HUANG Bin

2018-02-01

Full Text Available [Objectives] How to maintain propulsion capability in a CODOG propulsion system damage situation has important significance. [Methods] A ‘Hull-Engine-CPP-Rudder’ simulation model of a CODOG marine power plant is established on Simulink using the modularized method, and a dissymmetrical main engine urgent working mode is proposed and simulated. [Results] The results show that in the dissymmetrical working mode, two different engines cannot work simultaneously at designed capacity. However, by adjusting the pitch of the CPP, one engine can work at designed capacity and the other can work at partial load capacity; under this working mode, if high speed is demanded, the gas turbine should work at designed capacity. The CPP pitch driven by diesel should be maintained at a high value near the maximum. The maximum speed of this working mode is 84.4% of the designed speed, which is higher than the speed of the single shaft working mode driven by a gas turbine. [Conclusions] The research results of this paper can provide useful references for the design of ship propulsion systems.

Analysis Of Resistance And Effective Wake Friction Due To Addition Of Stern Tunnels On Passenger Ship Using Cfd

Science.gov (United States)

Chrismianto, D.; Tuswan; Manik, P.

2018-03-01

In this study, the stern tunnel to improve the efficiency of ship propulsion system is analysed. Stern tunnels installed on the two sides of the ship stern. Analysis of ship resistance and wake friction of the ship using CFD are carried out. The stern tunnel height (Hw) and length (L) are implemented to find the better stern tunnel form of the ship. The result of analysis showed that model has a high stern tunnels (Hw) of 1,444 m or additional high stern tunnels ratio of 16% and stern long tunnels (L) about 7 m is a model that has the smallest resistance about 1.1137 N or able to make reduction of resistance amount 11.2582%. While, the model with the addition of height of 0.2 m and a length of 9 m of stern tunnel is a model that has the better advanced speed about 4,927% in increase, and better wake friction about 30.4% in reduce.

LO2/LH2 propulsion for outer planet orbiter spacecraft

Science.gov (United States)

Garrison, P. W.; Sigurdson, K. B.

1983-01-01

Galileo class orbiter missions (750-1500 kg) to the outer planets require a large postinjection delta-V for improved propulsion performance. The present investigation shows that a pump-fed low thrust LO2/LH2 propulsion system can provide a significantly larger net on-orbit mass for a given delta-V than a state-of-the-art earth storable, N2O4/monomethylhydrazine pressure-fed propulsion system. A description is given of a conceptual design for a LO2/LH2 pump-fed propulsion system developed for a Galileo class mission to the outer planets. Attention is given to spacecraft configuration, details regarding the propulsion system, the thermal control of the cryogenic propellants, and aspects of mission performance.

Fusion propulsion systems

International Nuclear Information System (INIS)

Haloulakos, V.E.; Bourque, R.F.

1989-01-01

The continuing and expanding national efforts in both the military and commercial sectors for exploration and utilization of space will require launch, assembly in space, and orbital transfer of large payloads. The currently available delivery systems, utilizing various forms of chemical propulsion, do not have the payload capacity to fulfill the planned missions. National planning documents such as Air Force Project Forecast II and the National Commission on Space Report to the President contain numerous missions and payload delivery schedules that are beyond the present capabilities of the available systems, such as the Space Shuttle and the Expendable Launch Vehicles (ELVs). The need, therefore, is very pressing to design, develop, and deploy propulsion systems that offer a quantum level increase in delivered performance. One such potential system is fusion propulsion. This paper summarizes the result of an Air Force Astronautics Laboratory (AFAL) sponsored study of fusion propulsion conducted by the McDonnell Douglas Astronautics Company (MDAC), and its subcontractor General Atomics This study explored the potential of fusion propulsion for Air Force missions. Fusion fuels and existing confinement concepts were evaluated according to elaborate criteria. Two fuels, deuterium-tritium and deuterium-helium 3 (D- 3 He) were considered worthy of further consideration. D- 3 He was selected as the most attractive for this Air Force study. The colliding translating compact torus confinement concept was evaluated in depth and found to possibly possess the low mass and compactness required. Another possible concept is inertial confinement with the propellant surrounding the target. 5 refs., 5 figs., 8 tabs

The analysis of thermal-hydraulic performances of nuclear ship reactor

International Nuclear Information System (INIS)

Wakabayashi, Shinshichi; Hamada, Masao

1975-01-01

Thermal-hydraulic performances in the core of nuclear ship reactor was analysed by thermal-hydraulic analyser codes, AMRTC and COBRA-11+DNBCAL. This reactor is of a pressurized water type and incorporates the steam generator within the reactor vessel with the rated power of 330 MWt, which is developed by Nuclear Ship Research Panel Seven (NSR-7) in The Shipbuilding Research Association of Japan. Fuel temperature distributions, coolant temperature distributions, void fractions in coolant and minimum burn out ratio etc. were calculated. Results are as follows; a) The maximum temperature of fuel center is 1,472 0 C that corresponds to 53% as small as the melting point (2,800 0 C). b) Subcooled boiling exists in the core and the maximum void fraction is less than 4%. c) The minimum burn out ratio is not less than the minimum allowable limit of 1.25. It was found from the results of analysis that this reactor was able to be operated wide margin with respect to thermal-hydraulic design limits at the rated power. (auth.)

Impact of Emissions from Commercial Shipping During TexAQS 2006

Science.gov (United States)

Williams, E.; Lerner, B.; Murphy, P.

2007-12-01

Commercial marine vessels range in size from small fishing boats (20-30 meters in length) to extremely large container ships (over 300 meters in length). These ships almost without exception use diesel engines for propulsion and auxiliary power generation. The larger ships, comprising bulk carriers, tankers and container carriers, utilize diesel engines that produce power in the 10 MW to 100 MW range. These engines typically consume heavy fuel oils which are high in sulfur content (1%-4.5% by weight). These engines are also extremely efficient, converting essentially all of the carbon in the fuel to CO2, but also emitting NOx, CO, SO2, VOCs, and PM. During TexAQS 2006 our measurements on board the NOAA research ship Ronald H. Brown allowed us to characterize the emissions from a large number of commercial marine vessels. The measurements provided the means to calculate mass-based emission factors for many of the compounds noted above. With the information broadcast by these vessels over the Automated Information System, we have unequivocally determined the emission factors for over 200 vessels both at dock and underway. Our data largely confirm published average emission factors, but also show significant variability especially with NOx. This talk will present those results and then use the data to show that emissions of NOx and SO2 from these vessels are not negligible in the Houston-Galveston region.

Propulsive performance of pitching foils with variable chordwise flexibility

Science.gov (United States)

Zeyghami, Samane; Moored, Keith; Lehigh University Team

2017-11-01

Many swimming and flying animals propel themselves efficiently through water by oscillating flexible fins. These fins are not homogeneously flexible, but instead their flexural stiffness varies along their chord and span. Here we seek to evaluate the effect stiffness profile on the propulsive performance of pitching foils. Stiffness profile characterizes the variation in the local fin stiffness along the chord. To this aim, we developed a low order model of a functionally-graded material where the chordwise flexibility is modeled by two torsional springs along the chordline and the stiffness and location of the springs can be varied arbitrarily. The torsional spring structural model is then strongly coupled to a boundary element fluid model to simulate the fluid-structure interactions. Keeping the leading edge kinematics unchanged, we alter the stiffness profile of the foil and allow it to swim freely in response to the resulting hydrodynamic forces. We then detail the dependency of the hydrodynamic performance and the wake structure to the variations in the local structural properties of the foil.

Fitting aerodynamics and propulsion into the puzzle

Science.gov (United States)

Johnston, Patrick J.; Whitehead, Allen H., Jr.; Chapman, Gary T.

1987-01-01

The development of an airbreathing single-stage-to-orbit vehicle, in particular the problems of aerodynamics and propulsion integration, is examined. The boundary layer transition on constant pressure surfaces at hypersonic velocities, and the effects of noise on the transition are investigated. The importance of viscosity, real-gas effects, and drag at hypersonic speeds is discussed. A propulsion system with sufficient propulsive lift to enhance the performance of the vehicle is being developed. The difficulties of engine-airframe integration are analyzed.

Do Eco-rating Schemes Improve the Environmental Performance of Ships?

DEFF Research Database (Denmark)

Poulsen, René Taudal; Hermann, Roberto Rivas; Smink, Carla K.

2018-01-01

of ships. Extending the private environmental governance literature into a mature service industry with global operations, the paper shows that concerns about eco-rating schemes’ effectiveness also have relevance here. Shipping eco-rating schemes fall short of best practices for design and governance...

Energy and exergy analysis of a cruise ship

DEFF Research Database (Denmark)

Baldi, Francesco; Ahlgren, Fredrik; Nguyen, Tuong-Van

2015-01-01

but increasing share of the industry. The complexity of the energy system of a s hip where the energy required by propulsion is no longer the trivial main contributor to the whole energy use thus makes this kind of ship of particular interest for the analysis of how energy is converted from its original form...... destruction is generated in the Diesel engines and in the oil - fired boilers) and in the sea water cooler (5.4%) ; the main exergy losses happen instead in the exhaust gas, mostly from the main engines (6 7% of total losses) and particularly from those not equipped with heat recovery devices . The improved...

State-of-the-Art for Small Satellite Propulsion Systems

Science.gov (United States)

Parker, Khary I.

2016-01-01

SmallSats are a low cost access to space with an increasing need for propulsion systems. NASA, and other organizations, will be using SmallSats that require propulsion systems to: a) Conduct high quality near and far reaching on-orbit research and b) Perform technology demonstrations. Increasing call for high reliability and high performing for SmallSat components. Many SmallSat propulsion technologies are currently under development: a) Systems at various levels of maturity and b) Wide variety of systems for many mission applications.

Volume Dynamics Propulsion System Modeling for Supersonics Vehicle Research

Science.gov (United States)

Kopasakis, George; Connolly, Joseph W.; Paxson, Daniel E.; Ma, Peter

2010-01-01

Under the NASA Fundamental Aeronautics Program the Supersonics Project is working to overcome the obstacles to supersonic commercial flight. The proposed vehicles are long slim body aircraft with pronounced aero-servo-elastic modes. These modes can potentially couple with propulsion system dynamics; leading to performance challenges such as aircraft ride quality and stability. Other disturbances upstream of the engine generated from atmospheric wind gusts, angle of attack, and yaw can have similar effects. In addition, for optimal propulsion system performance, normal inlet-engine operations are required to be closer to compressor stall and inlet unstart. To study these phenomena an integrated model is needed that includes both airframe structural dynamics as well as the propulsion system dynamics. This paper covers the propulsion system component volume dynamics modeling of a turbojet engine that will be used for an integrated vehicle Aero-Propulso-Servo-Elastic model and for propulsion efficiency studies.

FY2015 Propulsion Materials Annual Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2016-12-30

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machines [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.

An Intelligent Propulsion Control Architecture to Enable More Autonomous Vehicle Operation

Science.gov (United States)

Litt, Jonathan S.; Sowers, T. Shane; Simon, Donald L.; Owen, A. Karl; Rinehart, Aidan W.; Chicatelli, Amy K.; Acheson, Michael J.; Hueschen, Richard M.; Spiers, Christopher W.

2018-01-01

This paper describes an intelligent propulsion control architecture that coordinates with the flight control to reduce the amount of pilot intervention required to operate the vehicle. Objectives of the architecture include the ability to: automatically recognize the aircraft operating state and flight phase; configure engine control to optimize performance with knowledge of engine condition and capability; enhance aircraft performance by coordinating propulsion control with flight control; and recognize off-nominal propulsion situations and to respond to them autonomously. The hierarchical intelligent propulsion system control can be decomposed into a propulsion system level and an individual engine level. The architecture is designed to be flexible to accommodate evolving requirements, adapt to technology improvements, and maintain safety.

H∞ robust control of load frequency in diesel-battery hybrid electric propulsion ship

Directory of Open Access Journals (Sweden)

LI Hongyue

2017-05-01

Full Text Available Considering the load frequency fluctuation in the shipboard integrated power system caused by such stochastic uncertainty as wind, wave and current, the battery is adopted here to compensate for the difference between diesel generator output power and ship demand power, and the secondary frequency control is used for the diesel generator to guarantee the power balance in the shipboard integrated power system and suppress the frequency fluctuation. The load frequency control problem is modeled as a state space equation, the robust controller is designed by selecting the appropriate sensitivity function and complementary sensitivity function based on the H∞ mixed sensitivity principle, and the controller is solved by the linear matrix inequality(LMIapproach. The amplitude frequency characteristics denote the reasonability of the designed controller and the design requirement is satisfied by the impact of the impulse signal. The simulation results show that, compared with the classical PI controller, the controller designed by the H∞ robust method can significantly suppress frequency fluctuation under stochastic uncertainty, and improve the power variation of the diesel generator, battery and state of charge(SOC. The robust stability and robust performance of the power system are also advanced.

Laser Propulsion - Is it another myth or a real potential?

International Nuclear Information System (INIS)

Cook, Joung R.

2008-01-01

This paper discusses different principles of inducing propulsive power using lasers and examines the performance limits along with pros and cons with respect to different space propulsion applications: satellite launching, orbital transfer, space debris clearing, satellite propulsion, and space travels. It concludes that a use of electrical propulsion, in conjunction with laser power beaming, is the most feasible application with technological and economic advantages for commercial use within the next decades

Estimates of fire environments in ship holds containing radioactive material packages

International Nuclear Information System (INIS)

Koski, J.A.; Cole, J.K.; Hohnstreiter, G.F.; Wix, S.D.

1995-01-01

Fire environments that occur on cargo ships differ significantly from the fire environments found in land transport. Cargo ships typically carry a large amount of flammable fuel for propulsion and shipboard power, and may transport large quantities of flammable cargo. As a result, sea mode transport accident records contain instances of long lasting and intense fires. Since Irradiated Nuclear Fuel (INF) casks are not carried on tankers with large flammable cargoes, most of these dramatic, long burning fires are not relevant threats, and transport studies must concentrate on those fires that are most likely to occur. By regulation, INF casks must be separated from flammable cargoes by a fire-resistant, liquid-tight partition. This makes a fire in an adjacent ship hold the most likely fire threat. The large size of a cargo ship relative to any spent nuclear fuel casks on board, however, may permit a severe, long lasting fire to occur with little or no thermal impact on the casks. Although some flammable materials such as shipping boxes or container floors may exist in the same hold with the cask, the amount of fuel available may not provide a significant threat to the massive transport casks used for radioactive materials. This shipboard fire situation differs significantly from the regulatory conditions specified in 10 CFR 71 for a fully engulfing pool fire. To learn more about the differences, a series of simple thermal analyses has been completed to estimate cask behavior in likely marine and land thermal accident situations. While the calculations are based on several conservative assumptions, and are only preliminary, they illustrate that casks are likely to heat much more slowly in shipboard hold fires than in an open pool fire. The calculations also reinforce the basic regulatory concept that for radioactive materials, the shipping cask, not the ship, is the primary protection barrier to consider

STATIC TESTS OF UNCONVENTIONAL PROPULSION UNITS FOR ULTRALIGHT AIRPLANES

Directory of Open Access Journals (Sweden)

Martin Helmich

2014-06-01

Full Text Available This paper presents static tests of a new unconventional propulsion unit for small aviation airplanes. Our laboratory stand – a fan drive demonstrator – enables us to compare various design options. We performed experiments to verify the propulsion functionality and a measurement procedure to determine the available thrust of the propulsion unit and its dependence on engine speed. The results used for subsequent optimization include the operating parameters of the propulsion unit, and the temperature and velocity fields in parts of the air duct.

Airbreathing Propulsion An Introduction

CERN Document Server

Bose, Tarit

2012-01-01

Airbreathing Propulsion covers the physics of combustion, fluid and thermo-dynamics, and structural mechanics of airbreathing engines, including piston, turboprop, turbojet, turbofan, and ramjet engines. End-of-chapter exercises allow the reader to practice the fundamental concepts behind airbreathing propulsion, and the included PAGIC computer code will help the reader to examine the relationships between the performance parameters of different engines. Large amounts of data on many different piston, turbojet, and turboprop engines have been compiled for this book and are included as an appendix. This textbook is ideal for senior undergraduate and graduate students studying aeronautical engineering, aerospace engineering, and mechanical engineering.

Development of alternative ship propulsion in terms of exhaust emissions

Directory of Open Access Journals (Sweden)

Markowski Jarosław

2016-01-01

Full Text Available The introduction of new emission limits for exhaust emissions of ship engines contributes to the development of new powertrain solutions. New solutions in the simplest approach concern the reduction of the concentration of sulfur in motor fuels. Typically, the aforementioned fuels have a lower value of viscosity which causes a number of supply system problems. It is becoming more and more common to use fuel cells in engine rooms of various types of marine vessels. Unlike conventional systems that use internal combustion engines, these systems have zero exhaust emissions. Hydrogen, methanol, methane and other substances may be used as a fuel in fuel cells. However, so far the best operating parameters are manifested by cells powered by hydrogen, which is associated with difficulties in obtaining and storing this fuel. Therefore, the use of turbine engines allows the obtaining of large operating and environmental advantages. The paper presents a comparison of the ecological parameters of turbine and piston engines.

New start of nuclear-powered ship 'Mutsu'. 2. On decommissioning works

International Nuclear Information System (INIS)

Matsuo, Ryusuke

1996-01-01

It was decided that 'Mutsu' is decommissioned immediately after the finish of the experimental voyage in the fundamental plan. Therefore, Nuclear-powered Ship Decommissioning Department was organized in Japan Atomic Energy Research Institute in 1992, and the investigation was begun on the measures to abolish the reactor facilities of 'Mutsu'. The fundamental plan was decided to adopt the removal and isolation method for the reactor room including the reactor and shields, to use the ship as the conventional propulsion ocean research ship, and to exhibit the removed reactor chamber under proper control. The required technical assessment and safety examination were carried out based on this fundamental plan. The technical feasibility studies were carried out on the safety of placing 'Mutsu' on a semisubmersible barge, the safety of the cutting works of the hull, the safety of a floating crane, and the safety at the time of accidents. Taking-out of fuel assemblies, the removal works of machinery and equipment in the reactor auxiliary machine room and others, the removal and transport works of the reactor room in a lump, the construction works of the preservation building, and the safety control on the decommissioning works are described. (K.I.)

The concept of underground nuclear heat and power plants (UNHPP) of upgraded safety, developed on the basis of ship-building technologies

International Nuclear Information System (INIS)

Pashin, V.M.; Petrov, Eh.L.; Shalik, G.P.; Khazov, B.S.; Malyshev, S.P.

1996-01-01

A concept of underground nuclear heat and power plants (UNHPP) of upgraded safety on the basis of ship-building technologies is considered, in which the priority is set to population security and environmental protection. Ways of realization of ziro radiation risk for the population residing in a close vicinity of UNHPP are substantiated. basic principles of the concept are formulated which envisage the use of ship propulsion reactor facilities that have been multiply tested in operation. The sources of economic competitiveness of UNHPPs, as compared with the existing NPPs, are shown

Propulsion Systems Panel deliberations

Science.gov (United States)

Bianca, Carmelo J.; Miner, Robert; Johnston, Lawrence M.; Bruce, R.; Dennies, Daniel P.; Dickenson, W.; Dreshfield, Robert; Karakulko, Walt; Mcgaw, Mike; Munafo, Paul M.

1993-01-01

The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. This panel was co-chaired by Carmelo Bianca, MSFC, and Bob Miner, LeRC. Because of the diverse range of missions anticipated for the Space Transportation program, three distinct propulsion system types were identified in the workshop planning process: liquid propulsion systems, solid propulsion systems and nuclear electric/nuclear thermal propulsion systems.

Primary electric propulsion thrust subsystem definition

Science.gov (United States)

Masek, T. D.; Ward, J. W.; Kami, S.

1975-01-01

A review is presented of the current status of primary propulsion thrust subsystem (TSS) performance, packaging considerations, and certain operational characteristics. Thrust subsystem related work from recent studies by Jet Propulsion Laboratories (JPL), Rockwell and Boeing is discussed. Existing performance for 30-cm thrusters, power processors and TSS is present along with projections for future improvements. Results of analyses to determine (1) magnetic field distributions resulting from an array of thrusters, (2) thruster emitted particle flux distributions from an array of thrusters, and (3) TSS element failure rates are described to indicate the availability of analytical tools for evaluation of TSS designs.

Aero-Propulsive Model Design from a Commercial Aircraft in Climb and Cruise Regime using Performance Data =

Science.gov (United States)

Tudor, Magdalena

IATA has estimated, in 2012, at about 2% of global carbon dioxide emissions, the environmental impact of the air transport, as a consequence caused by the rapidly growing of global movement demand of people and goods, and which was effectively taken into account in the development of the aviation industry. The historic achievements of scientific and technical progress in the field of commercial aviation were contributed to this estimate, and even today the research continues to make progress to help to reduce the emissions of greenhouse gases. Advances in commercial aircraft, and its engine design technology had the aim to improve flight performance. These improvements have enhanced the global flight planning of these types of aircrafts. Almost all of these advances rely on generated performance data as reference sources, the most of which are classified as "confidential" by the aircraft manufacturers. There are very few aero-propulsive models conceived for the climb regime in the literature, but none of them was designed without access to an engine database, and/or to performance data in climb and in cruise regimes with direct applicability for flight optimization. In this thesis, aero-propulsive models methodologies are proposed for climb and cruise regimes, using system identification and validation methods, through which airplane performance can be computed and stored in the most compact and easily accessible format for this kind of performance data. The acquiring of performance data in this format makes it possible to optimize flight profiles, used by on-board Flight Management Systems. The aero-propulsive models developed here were investigated on two aircrafts belonging to commercial class, and both of them had offered very good accuracy. One of their advantages is that they can be adapted to any other aircraft of the same class, even if there is no access to their corresponding engine flight data. In addition, these models could save airlines a considerable

Propulsion Powertrain Real-Time Simulation Using Hardware-in-the-Loop (HIL) for Aircraft Electric Propulsion System

Science.gov (United States)

Choi, Benjamin B.; Brown, Gerald V.

2017-01-01

It is essential to design a propulsion powertrain real-time simulator using the hardware-in-the-loop (HIL) system that emulates an electrified aircraft propulsion (EAP) systems power grid. This simulator would enable us to facilitate in-depth understanding of the system principles, to validate system model analysis and performance prediction, and to demonstrate the proof-of-concept of the EAP electrical system. This paper describes how subscale electrical machines with their controllers can mimic the power components in an EAP powertrain. In particular, three powertrain emulations are presented to mimic 1) a gas turbo-=shaft engine driving a generator, consisting of two permanent magnet (PM) motors with brushless motor drives, coupled by a shaft, 2) a motor driving a propulsive fan, and 3) a turbo-shaft engine driven fan (turbofan engine) operation. As a first step towards the demonstration, experimental dynamic characterization of the two motor drive systems, coupled by a mechanical shaft, were performed. The previously developed analytical motor models1 were then replaced with the experimental motor models to perform the real-time demonstration in the predefined flight path profiles. This technique can convert the plain motor system into a unique EAP power grid emulator that enables rapid analysis and real-time simulation performance using hardware-in-the-loop (HIL).

Mathematical model of marine diesel engine simulator for a new methodology of self propulsion tests

Energy Technology Data Exchange (ETDEWEB)

Izzuddin, Nur; Sunarsih,; Priyanto, Agoes [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia)

2015-05-15

As a vessel operates in the open seas, a marine diesel engine simulator whose engine rotation is controlled to transmit through propeller shaft is a new methodology for the self propulsion tests to track the fuel saving in a real time. Considering the circumstance, this paper presents the real time of marine diesel engine simulator system to track the real performance of a ship through a computer-simulated model. A mathematical model of marine diesel engine and the propeller are used in the simulation to estimate fuel rate, engine rotating speed, thrust and torque of the propeller thus achieve the target vessel’s speed. The input and output are a real time control system of fuel saving rate and propeller rotating speed representing the marine diesel engine characteristics. The self-propulsion tests in calm waters were conducted using a vessel model to validate the marine diesel engine simulator. The simulator then was used to evaluate the fuel saving by employing a new mathematical model of turbochargers for the marine diesel engine simulator. The control system developed will be beneficial for users as to analyze different condition of vessel’s speed to obtain better characteristics and hence optimize the fuel saving rate.

Deployable Propulsion, Power and Communication Systems for Solar System Exploration

Science.gov (United States)

Johnson, Les; Carr, John A.; Boyd, Darren

2017-01-01

NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, and miniaturized electronics, new mission-level capabilities will be enabled aboard lower-cost small spacecraft instead of their more expensive, traditional counterparts, enabling a new generation of frequent, inexpensive deep space missions. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication. Like their name implies, solar sails 'sail' by reflecting sunlight from a large, lightweight reflective material that resembles the sails of 17th and 18th century ships and modern sloops. Instead of wind, the sail and the ship derive their thrust by reflecting solar photons. Solar sail technology has been discussed in the literature for quite some time, but it is only since 2010 that sails have been proven to work in space. Thin-film photovoltaics are revolutionizing the terrestrial power generation market and have been found to be suitable for medium-term use in the space environment. When mounted on the thin-film substrate, these photovoltaics can be packaged into very small volumes and used to generate significant power for small spacecraft. Finally, embedded antennas are being developed that can be adhered to thin-film substrates to provide lightweight, omnidirectional UHF and X-band coverage, increasing bandwidth or effective communication ranges for small spacecraft. Taken together, they may enable a host of new deep space destinations to be reached by a generation of spacecraft smaller and more capable than ever before.

Powersail High Power Propulsion System Design Study

Science.gov (United States)

Gulczinski, Frank S., III

2000-11-01

A desire by the United States Air Force to exploit the space environment has led to a need for increased on-orbit electrical power availability. To enable this, the Air Force Research Laboratory Space Vehicles Directorate (AFRL/ VS) is developing Powersail: a two-phased program to demonstrate high power (100 kW to 1 MW) capability in space using a deployable, flexible solar array connected to the host spacecraft using a slack umbilical. The first phase will be a proof-of-concept demonstration at 50 kW, followed by the second phase, an operational system at full power. In support of this program, the AFRL propulsion Directorate's Spacecraft Propulsion Branch (AFRL/PRS ) at Edwards AFB has commissioned a design study of the Powersail High Power Propulsion System. The purpose of this study, the results of which are summarized in this paper, is to perform mission and design trades to identify potential full-power applications (both near-Earth and interplanetary) and the corresponding propulsion system requirements and design. The design study shall farther identify a suitable low power demonstration flight that maximizes risk reduction for the fully operational system. This propulsion system is expected to be threefold: (1) primary propulsion for moving the entire vehicle, (2) a propulsion unit that maintains the solar array position relative to the host spacecraft, and (3) control propulsion for maintaining proper orientation for the flexible solar array.

Optimal load allocation of complex ship power plants

International Nuclear Information System (INIS)

Baldi, Francesco; Ahlgren, Fredrik; Melino, Francesco; Gabrielii, Cecilia; Andersson, Karin

2016-01-01

Highlights: • The optimal operation of the prime movers of hybrid ship power plants is addressed. • Both mechanical, electric and thermal power demand are considered. • The problem is modelled as a mixed integer-nonlinear programming problem. • Up to 3% savings can be achieved with hybrid power plants. • Including the thermal power demand improves the solution by up to 4%. - Abstract: In a world with increased pressure on reducing fuel consumption and carbon dioxide emissions, the cruise industry is growing in size and impact. In this context, further effort is required for improving the energy efficiency of cruise ship energy systems. In this paper, we propose a generic method for modelling the power plant of an isolated system with mechanical, electric and thermal power demands and for the optimal load allocation of the different components that are able to fulfil the demand. The optimisation problem is presented in the form of a mixed integer linear programming (MINLP) problem, where the number of engines and/or boilers running is represented by the integer variables, while their respective load is represented by the non-integer variables. The individual components are modelled using a combination of first-principle models and polynomial regressions, thus making the system nonlinear. The proposed method is applied to the load-allocation problem of a cruise ship sailing in the Baltic Sea, and used to compare the existing power plant with a hybrid propulsion plant. The results show the benefits brought by using the proposing method, which allow estimating the performance of the hybrid system (for which the load allocation is a non-trivial problem) while also including the contribution of the heat demand. This allows showing that, based on a reference round voyage, up to 3% savings could be achieved by installing the proposed system, compared to the existing one, and that a NPV of 11 kUSD could be achieved already 5 years after the installation of the

Propulsion Laboratory

Data.gov (United States)

Federal Laboratory Consortium — The Propulsion Lab simulates field test conditions in a controlled environment, using standardized or customized test procedures. The Propulsion Lab's 11 cells can...

Advanced Chemical Propulsion for Science Missions

Science.gov (United States)

Liou, Larry

2008-01-01

The advanced chemical propulsion technology area of NASA's In-Space Technology Project is investing in systems and components for increased performance and reduced cost of chemical propulsion technologies applicable to near-term science missions. Presently the primary investment in the advanced chemical propulsion technology area is in the AMBR high temperature storable bipropellant rocket engine. Scheduled to be available for flight development starting in year 2008, AMBR engine shows a 60 kg payload gain in an analysis for the Titan-Enceladus orbiter mission and a 33 percent manufacturing cost reduction over its baseline, state-of-the-art counterpart. Other technologies invested include the reliable lightweight tanks for propellant and the precision propellant management and mixture ratio control. Both technologies show significant mission benefit, can be applied to any liquid propulsion system, and upon completion of the efforts described in this paper, are at least in parts ready for flight infusion. Details of the technologies are discussed.

Ionic liquid propellants: future fuels for space propulsion.

Science.gov (United States)

Zhang, Qinghua; Shreeve, Jean'ne M

2013-11-11

Use of green propellants is a trend for future space propulsion. Hypergolic ionic liquid propellants, which are environmentally-benign while exhibiting energetic performances comparable to hydrazine, have shown great potential to meet the requirements of developing nontoxic high-performance propellant formulations for space propulsion applications. This Concept article presents a review of recent advances in the field of ionic liquid propellants. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Integrated propulsion for near-Earth space missions. Volume 2: Technical

Science.gov (United States)

Dailey, C. L.; Meissinger, H. F.; Lovberg, R. H.; Zafran, S.

1981-01-01

The calculation approach is described for parametric analysis of candidate electric propulsion systems employed in LEO to GEO missions. Occultation relations, atmospheric density effects, and natural radiation effects are presented. A solar cell cover glass tradeoff is performed to determine optimum glass thickness. Solar array and spacecraft pointing strategies are described for low altitude flight and for optimum array illumination during ascent. Mass ratio tradeoffs versus transfer time provide direction for thruster technology improvements. Integrated electric propulsion analysis is performed for orbit boosting, inclination change, attitude control, stationkeeping, repositioning, and disposal functions as well as power sharing with payload on orbit. Comparison with chemical auxiliary propulsion is made to quantify the advantages of integrated propulsion in terms of weight savings and concomittant launch cost savings.

IMPULSE---an advanced, high performance nuclear thermal propulsion system

International Nuclear Information System (INIS)

Petrosky, L.J.; Disney, R.K.; Mangus, J.D.; Gunn, S.A.; Zweig, H.R.

1993-01-01

IMPULSE is an advanced nuclear propulsion engine for future space missions based on a novel conical fuel. Fuel assemblies are formed by stacking a series of truncated (U, Zr)C cones with non-fueled lips. Hydrogen flows radially inward between the cones to a central plenum connected to a high performance bell nozzle. The reference IMPULSE engine rated at 75,000 lb thrust and 1800 MWt weighs 1360 kg and is 3.65 meters in height and 81 cm in diameter. Specific impulse is estimated to be 1000 for a 15 minute life at full power. If longer life times are required, the operating temperature can be reduced with a concomitant decrease in specific impulse. Advantages of this concept include: well defined coolant paths without outlet flow restrictions; redundant orificing; very low thermal gradients and hence, thermal stresses, across the fuel elements; and reduced thermal stresses because of the truncated conical shape of the fuel elements

Preliminary Assessment of Using Gelled and Hybrid Propellant Propulsion for VTOL/SSTO Launch Systems

Science.gov (United States)

Palaszewski, Bryan; OLeary, Robert; Pelaccio, Dennis G.

1998-01-01

A novel, reusable, Vertical-Takeoff-and-Vertical-Takeoff-and-Landing, Single-Stage-to-Orbit (VTOL/SSTO) launch system concept, named AUGMENT-SSTO, is presented in this paper to help quantify the advantages of employing gelled and hybrid propellant propulsion system options for such applications. The launch vehicle system concept considered uses a highly coupled, main high performance liquid oxygen/liquid hydrogen (LO2/LH2) propulsion system, that is used only for launch, while a gelled or hybrid propellant propulsion system auxiliary propulsion system is used during final orbit insertion, major orbit maneuvering, and landing propulsive burn phases of flight. Using a gelled or hybrid propellant propulsion system for major orbit maneuver burns and landing has many advantages over conventional VTOL/SSTO concepts that use LO2/LH2 propulsion system(s) burns for all phases of flight. The applicability of three gelled propellant systems, O2/H2/Al, O2/RP-1/Al, and NTO/MMH/Al, and a state-of-the-art (SOA) hybrid propulsion system are examined in this study. Additionally, this paper addresses the applicability of a high performance gelled O2/H2 propulsion system to perform the primary, as well as the auxiliary propulsion system functions of the vehicle.

Sprint performance and propulsion asymmetries on an ergometer in trained high- and low-point wheelchair rugby players

NARCIS (Netherlands)

Goosey-Tolfrey, Victoria L; Vegter, Riemer J K; Mason, Barry S; Paulson, Thomas A W; Lenton, John P; van der Scheer, Jan W; van der Woude, Lucas H V

The purpose of this study was to examine the propulsion asymmetries of wheelchair athletes while sprinting on an instrumented, dual-roller ergometer system. Eighteen experienced wheelchair rugby players (8 low point (LP) (class 1.5) and 10 high point (HP) (class 2.0)) performed a 15-second sprint in

Hierarchical Discrete Event Supervisory Control of Aircraft Propulsion Systems

Science.gov (United States)

Yasar, Murat; Tolani, Devendra; Ray, Asok; Shah, Neerav; Litt, Jonathan S.

2004-01-01

This paper presents a hierarchical application of Discrete Event Supervisory (DES) control theory for intelligent decision and control of a twin-engine aircraft propulsion system. A dual layer hierarchical DES controller is designed to supervise and coordinate the operation of two engines of the propulsion system. The two engines are individually controlled to achieve enhanced performance and reliability, necessary for fulfilling the mission objectives. Each engine is operated under a continuously varying control system that maintains the specified performance and a local discrete-event supervisor for condition monitoring and life extending control. A global upper level DES controller is designed for load balancing and overall health management of the propulsion system.

FY2016 Propulsion Materials Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None, None

2017-05-01

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines and Fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.

Nuclear propulsion for the space exploration initiative

International Nuclear Information System (INIS)

Stanley, M.L.

1991-01-01

President Bush's speech of July 20, 1989, outlining a goal to go back to the moon and then Mars initiated the Space Exploration Initiative (SEI). The US Department of Defense (DOD), US Department of Energy (DOE), and NASA have been working together in the planning necessary to initiate a program to develop a nuclear propulsion system. Applications of nuclear technology for in-space transfer of personnel and cargo between Earth orbit and lunar or Martian orbit are being considered as alternatives to chemical propulsion systems. Mission and system concept studies conducted over the past 30 yr have consistently indicated that use of nuclear technology can substantially reduce in-space propellant requirements. A variety of nuclear technology options are currently being studied, including nuclear thermal rockets, nuclear electrical propulsion systems, and hybrid nuclear thermal rockets/nuclear electric propulsion concepts. Concept performance in terms of thrust, weight, power, and efficiency are dependent, and appropriate concept application is mission dependent (i.e., lunar, Mars, cargo, personnel, trajectory, transit time, payload). A comprehensive evaluation of mission application, technology performance capability and maturity, technology development programmatics, and safety characteristics is required to optimize both technology and mission selection to support the Presidential initiative

Worldwide Space Launch Vehicles and Their Mainstage Liquid Rocket Propulsion

Science.gov (United States)

Rahman, Shamim A.

2010-01-01

Space launch vehicle begins with a basic propulsion stage, and serves as a missile or small launch vehicle; many are traceable to the 1945 German A-4. Increasing stage size, and increasingly energetic propulsion allows for heavier payloads and greater. Earth to Orbit lift capability. Liquid rocket propulsion began with use of storable (UDMH/N2O4) and evolved to high performing cryogenics (LOX/RP, and LOX/LH). Growth versions of SLV's rely on strap-on propulsive stages of either solid propellants or liquid propellants.

MW-Class Electric Propulsion System Designs

Science.gov (United States)

LaPointe, Michael R.; Oleson, Steven; Pencil, Eric; Mercer, Carolyn; Distefano, Salvador

2011-01-01

Electric propulsion systems are well developed and have been in commercial use for several years. Ion and Hall thrusters have propelled robotic spacecraft to encounters with asteroids, the Moon, and minor planetary bodies within the solar system, while higher power systems are being considered to support even more demanding future space science and exploration missions. Such missions may include orbit raising and station-keeping for large platforms, robotic and human missions to near earth asteroids, cargo transport for sustained lunar or Mars exploration, and at very high-power, fast piloted missions to Mars and the outer planets. The Advanced In-Space Propulsion Project, High Efficiency Space Power Systems Project, and High Power Electric Propulsion Demonstration Project were established within the NASA Exploration Technology Development and Demonstration Program to develop and advance the fundamental technologies required for these long-range, future exploration missions. Under the auspices of the High Efficiency Space Power Systems Project, and supported by the Advanced In-Space Propulsion and High Power Electric Propulsion Projects, the COMPASS design team at the NASA Glenn Research Center performed multiple parametric design analyses to determine solar and nuclear electric power technology requirements for representative 300-kW class and pulsed and steady-state MW-class electric propulsion systems. This paper describes the results of the MW-class electric power and propulsion design analysis. Starting with the representative MW-class vehicle configurations, and using design reference missions bounded by launch dates, several power system technology improvements were introduced into the parametric COMPASS simulations to determine the potential system level benefits such technologies might provide. Those technologies providing quantitative system level benefits were then assessed for technical feasibility, cost, and time to develop. Key assumptions and primary

Energy Efficient and Environmentally Friendly Hybrid Conversion of Inland Passenger Vessel

Directory of Open Access Journals (Sweden)

Litwin Wojciech

2017-12-01

Full Text Available The development and growing availability of modern technologies, along with more and more severe environment protection standards which frequently take a form of legal regulations, are the reason why attempts are made to find a quiet and economical propulsion system not only for newly built watercraft units, but also for modernised ones. Correct selection of the propulsion and supply system for a given vessel affects significantly not only the energy efficiency of the propulsions system but also the environment - as this selection is crucial for the noise and exhaust emission levels. The paper presents results of experimental examination of ship power demand performed on a historic passenger ship of 25 m in length. Two variants, referred to as serial and parallel hybrid propulsion systems, were examined with respect to the maximum length of the single-day route covered by the ship. The recorded power demands and environmental impact were compared with those characteristic for the already installed conventional propulsion system. Taking into account a high safety level expected to be ensured on a passenger ship, the serial hybrid system was based on two electric motors working in parallel and supplied from two separate sets of batteries. This solution ensures higher reliability, along with relatively high energy efficiency. The results of the performed examination have revealed that the serial propulsion system is the least harmful to the environment, but its investment cost is the highest. In this context, the optimum solution for the ship owner seems to be a parallel hybrid system of diesel-electric type

Test facilities for evaluating nuclear thermal propulsion systems

International Nuclear Information System (INIS)

Beck, D.F.; Allen, G.C.; Shipers, L.R.; Dobranich, D.; Ottinger, C.A.; Harmon, C.D.; Fan, W.C.; Todosow, M.

1992-01-01

Interagency panels evaluating nuclear thermal propulsion (NTP) development options have consistently recognized the need for constructing a major new ground test facility to support fuel element and engine testing. This paper summarizes the requirements, configuration, and baseline performance of some of the major subsystems designed to support a proposed ground test complex for evaluating nuclear thermal propulsion fuel elements and engines being developed for the Space Nuclear Thermal Propulsion (SNTP) program. Some preliminary results of evaluating this facility for use in testing other NTP concepts are also summarized

Parametrical Method for Determining Optimal Ship Carrying Capacity and Performance of Handling Equipment

Directory of Open Access Journals (Sweden)

Michalski Jan P.

2016-04-01

Full Text Available The paper presents a method of evaluating the optimal value of the cargo ships deadweight and the coupled optimal value of cargo handling capacity. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper second hand ship for a given transportation task. The deadweight and the capacity are determined on the basis of a selected economic measure of the transport effectiveness of ship – the Required Freight Rate. The mathematical model of the problem is of a deterministic character and the simplifying assumptions are justified for ships operating in the liner trade. The assumptions are so selected that solution of the problem is obtained in analytical closed form. The presented method can be useful for application in the preliminary ship design or in the simulation of pre-investment transportation task studies.

On use of hybrid rocket propulsion for suborbital vehicles

Science.gov (United States)

Okninski, Adam

2018-04-01

While the majority of operating suborbital rockets use solid rocket propulsion, recent advancements in the field of hybrid rocket motors lead to renewed interest in their use in sounding rockets. This paper presents results of optimisation of sounding rockets using hybrid propulsion. An overview of vehicles under development during the last decade, as well as heritage systems is provided. Different propellant combinations are discussed and their performance assessment is given. While Liquid Oxygen, Nitrous Oxide and Nitric Acid have been widely tested with various solid fuels in flight, Hydrogen Peroxide remains an oxidiser with very limited sounding rocket applications. The benefits of hybrid propulsion for sounding rockets are given. In case of hybrid rocket motors the thrust curve can be optimised for each flight, using a flow regulator, depending on the payload and mission. Results of studies concerning the optimal burn duration and nozzle selection are given. Specific considerations are provided for the Polish ILR-33 "Amber" sounding rocket. Low regression rates, which up to date were viewed as a drawback of hybrid propulsion may be used to the benefit of maximising rocket performance if small solid rocket boosters are used during the initial flight period. While increased interest in hybrid propulsion is present, no up-to-date reference concerning use of hybrid rocket propulsion for sounding rockets is available. The ultimate goal of the paper is to provide insight into the sensitivity of different design parameters on performance of hybrid sounding rockets and delve into the potential and challenges of using hybrid rocket technology for expendable suborbital applications.

The Ion Propulsion System for the Solar Electric Propulsion Technology Demonstration Mission

Science.gov (United States)

Herman, Daniel A.; Santiago, Walter; Kamhawi, Hani; Polk, James E.; Snyder, John Steven; Hofer, Richard R.; Parker, J. Morgan

2015-01-01

The Asteroid Redirect Robotic Mission is a candidate Solar Electric Propulsion Technology Demonstration Mission whose main objectives are to develop and demonstrate a high-power solar electric propulsion capability for the Agency and return an asteroidal mass for rendezvous and characterization in a companion human-crewed mission. The ion propulsion system must be capable of operating over an 8-year time period and processing up to 10,000 kg of xenon propellant. This high-power solar electric propulsion capability, or an extensible derivative of it, has been identified as a critical part of an affordable, beyond-low-Earth-orbit, manned-exploration architecture. Under the NASA Space Technology Mission Directorate the critical electric propulsion and solar array technologies are being developed. The ion propulsion system being co-developed by the NASA Glenn Research Center and the Jet Propulsion Laboratory for the Asteroid Redirect Vehicle is based on the NASA-developed 12.5 kW Hall Effect Rocket with Magnetic Shielding (HERMeS0 thruster and power processing technologies. This paper presents the conceptual design for the ion propulsion system, the status of the NASA in-house thruster and power processing activity, and an update on flight hardware.

Nuclear propulsion for orbital transfer

International Nuclear Information System (INIS)

Beale, G.A.; Lawrence, T.J.

1989-01-01

The state of the art in nuclear propulsion for orbital transfer is discussed. Cryogenic propulsion, electric propulsion, solar-thermal propulsion and direct nuclear propulsion are examined in this context. New technologies with exceptional promise are addressed, emphasizing the particle test bed nuclear engine

Mini-review: Assessing the drivers of ship biofouling management--aligning industry and biosecurity goals.

Science.gov (United States)

Davidson, Ian; Scianni, Christopher; Hewitt, Chad; Everett, Richard; Holm, Eric; Tamburri, Mario; Ruiz, Gregory

2016-01-01

Biofouling exerts a frictional and cost penalty on ships and is a direct cause of invasion by marine species. These negative consequences provide a unifying purpose for the maritime industry and biosecurity managers to prevent biofouling accumulation and transfer, but important gaps exist between these sectors. This mini-review examines the approach to assessments of ship biofouling among sectors (industry, biosecurity and marine science) and the implications for existing and emerging management of biofouling. The primary distinctions between industry and biosecurity in assessment of vessels biofouling revolve around the resolution of biological information collected and the specific wetted surface areas of primary concern to each sector. The morphological characteristics of biofouling and their effects on propulsion dynamics are of primary concern to industry, with an almost exclusive focus on the vertical sides and flat bottom of hulls and an emphasis on antifouling and operational performance. In contrast, the identity, biogeography, and ecology of translocated organisms is of highest concern to invasion researchers and biosecurity managers and policymakers, especially as it relates to species with known histories of invasion elsewhere. Current management practices often provide adequate, although not complete, provision for hull surfaces, but niche areas are well known to enhance biosecurity risk. As regulations to prevent invasions emerge in this arena, there is a growing opportunity for industry, biosecurity and academic stakeholders to collaborate and harmonize efforts to assess and manage biofouling of ships that should lead to more comprehensive biofouling solutions that promote industry goals while reducing biosecurity risk and greenhouse gas emissions.

Propulsive efficiency of frog swimming with different feet and swimming patterns

Directory of Open Access Journals (Sweden)

Fan Jizhuang

2017-04-01

Full Text Available Aquatic and terrestrial animals have different swimming performances and mechanical efficiencies based on their different swimming methods. To explore propulsion in swimming frogs, this study calculated mechanical efficiencies based on data describing aquatic and terrestrial webbed-foot shapes and swimming patterns. First, a simplified frog model and dynamic equation were established, and hydrodynamic forces on the foot were computed according to computational fluid dynamic calculations. Then, a two-link mechanism was used to stand in for the diverse and complicated hind legs found in different frog species, in order to simplify the input work calculation. Joint torques were derived based on the virtual work principle to compute the efficiency of foot propulsion. Finally, two feet and swimming patterns were combined to compute propulsive efficiency. The aquatic frog demonstrated a propulsive efficiency (43.11% between those of drag-based and lift-based propulsions, while the terrestrial frog efficiency (29.58% fell within the range of drag-based propulsion. The results illustrate the main factor of swimming patterns for swimming performance and efficiency.

Aeronautic propulsion systems; Propulseurs aeronautiques

Energy Technology Data Exchange (ETDEWEB)

Lepourry, P; Ciryci, R

1992-12-31

This book is devoted to airplane pilots having a private licence and who would like to take up a professional rank. It comprises 8 chapters dealing with: the different type of propulsion systems, turbojet, turbofan and piston engines; the propeller (characteristics, different types, functioning, protection systems..); the piston engines (4-stroke cycle, power and efficiency, description, characteristics); the gas generator and its limitations (air intake, combustion chamber, turbines, nozzles, fuel systems..); the performances of propulsion systems; the drive, control and instruments; and the use of engines. The last chapter is a self-evaluation questionnaire about the notions developed in the book. (J.S.)

The effect of wheelchair propulsion style on changes in time spent in extreme wrist orientations after a bout of fatiguing propulsion.

Science.gov (United States)

Zukowski, Lisa A; Hass, Chris J; Shechtman, Orit; Christou, Evangelos A; Tillman, Mark D

2017-10-01

This study compared how wheelchair propulsion styles affect changes in percentage of time spent in extreme wrist orientations, which have been associated with median nerve injury, after a fatiguing bout of propulsion. Twenty novice, non-disabled adult males learned arcing (ARC) and semicircular (SEMI) propulsion styles and utilised each to perform a wheelchair fatigue protocol. ARC and SEMI did not significantly differ in terms of changes after the fatigue protocol in percentage of time spent in extreme flexion/extension or radial/ulnar deviation at the push phase beginning or end. A pattern was observed, although not significant, of greater increases in percentage of time spent in extreme wrist extension and ulnar deviation during the push phase beginning and ulnar deviation during the push phase end while utilising SEMI relative to ARC. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles. Practitioner Summary: How wheelchair propulsion styles change with fatigue in terms of extreme wrist orientations was examined. This study evinces that individual differences are greater than observed changes in extreme wrist orientations for both propulsion styles and point towards the need for future research on individual differences utilising propulsion styles.

Propulsion for CubeSats

Science.gov (United States)

Lemmer, Kristina

2017-05-01

At present, very few CubeSats have flown in space featuring propulsion systems. Of those that have, the literature is scattered, published in a variety of formats (conference proceedings, contractor websites, technical notes, and journal articles), and often not available for public release. This paper seeks to collect the relevant publically releasable information in one location. To date, only two missions have featured propulsion systems as part of the technology demonstration. The IMPACT mission from the Aerospace Corporation launched several electrospray thrusters from Massachusetts Institute of Technology, and BricSAT-P from the United States Naval Academy had four micro-Cathode Arc Thrusters from George Washington University. Other than these two missions, propulsion on CubeSats has been used only for attitude control and reaction wheel desaturation via cold gas propulsion systems. As the desired capability of CubeSats increases, and more complex missions are planned, propulsion is required to accomplish the science and engineering objectives. This survey includes propulsion systems that have been designed specifically for the CubeSat platform and systems that fit within CubeSat constraints but were developed for other platforms. Throughout the survey, discussion of flight heritage and results of the mission are included where publicly released information and data have been made available. Major categories of propulsion systems that are in this survey are solar sails, cold gas propulsion, electric propulsion, and chemical propulsion systems. Only systems that have been tested in a laboratory or with some flight history are included.

Reusable Reentry Satellite (RRS): Propulsion system trade study

Science.gov (United States)

1990-01-01

The purpose of the Reusable Reentry Satellite (RRS) Propulsion System Trade Study described in this summary report was to investigate various propulsion options available for incorporation on the RRS and to select the option best suited for RRS application. The design requirements for the RRS propulsion system were driven by the total impulse requirements necessary to operate within the performance envelope specified in the RRS System Requirements Documents. These requirements were incorporated within the Design Reference Missions (DRM's) identified for use in this and other subsystem trade studies. This study investigated the following propulsion systems: solid rocket, monopropellant, bipropellant (monomethyl hydrazine and nitrogen tetroxide or MMH/NTO), dual-mode bipropellant (hydrazine and nitrogen tetroxide or N2H4/NTO), liquid oxygen and liquid hydrogen (LO2/LH2), and an advanced design propulsion system using SDI-developed components. A liquid monopropellant blowdown propulsion system was found to be best suited for meeting the RRS requirements and is recommended as the baseline system. This system was chosen because it is the simplest of all investigated, has the fewest components, and is the most cost effective. The monopropellant system meets all RRS performance requirements and has the capability to provide a very accurate deorbit burn which minimizes reentry dispersions. In addition, no new hardware qualification is required for a monopropellant system. Although the bipropellant systems offered some weight savings capability for missions requiring large deorbit velocities, the advantage of a lower mass system only applies if the total vehicle design can be reduced to allow a cheaper launch vehicle to be used. At the time of this trade study, the overall RRS weight budget and launch vehicle selection were not being driven by the propulsion system selection. Thus, the added cost and complexity of more advanced systems did not warrant application.

A review of the status of, and prospects for, nuclear marine propulsion

International Nuclear Information System (INIS)

Edwards, J.

1976-01-01

It is stated that the matter of nuclear marine propulsion has been under consideration in the UK since 1957, at which time the Royal Navy commenced studies into the possibility of a nuclear powered 65,000 ton fleet support tanker. Nuclear warship studies started earlier in the USA, where studies were started in 1946 on the application of nuclear power to submarines and surface warships. The present position is that five nuclear merchant ships have been built, whereas 290 nuclear warships are either operational or building. Reference is made to a lecture given by the author in February 1974, in which the position at that time was reviewed, the present lecture up-dating that lecture with regard to subsequent events and their effects on the present prospects for nuclear merchant ships. Headings include the following: situation in early 1974; present situation; economic analyses; the energy situation; problems and prospects (economic assessments, inflation effects, safety requirements, construction time, refuelling requirements, ship residual value and decommissioning costs, training costs, insurance and indemnity, essential documentation, safety acceptance and port entry, licensing and legislative problems, accidents and their consequences); developments in marine reactor designs; and conclusions. The discussions are reproduced in full. (U.K.)

In-Situ EBCs for High Performance Composite Propulsion Components, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Silicon Carbide based ceramic matrix composites (CMCs) offer the potential to fundamentally change the design and manufacture of aeronautical and space propulsion...

In-situ EBCs for High Performance Composite Propulsion Components, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Silicon Carbide based ceramic matrix composites (CMCs) offer the potential to fundamentally change the design and manufacture of aeronautical and space propulsion...

Effect of workload setting on propulsion technique in handrim wheelchair propulsion.

Science.gov (United States)

van Drongelen, Stefan; Arnet, Ursina; Veeger, Dirkjan H E J; van der Woude, Lucas H V

2013-03-01

To investigate the influence of workload setting (speed at constant power, method to impose power) on the propulsion technique (i.e. force and timing characteristics) in handrim wheelchair propulsion. Twelve able-bodied men participated in this study. External forces were measured during handrim wheelchair propulsion on a motor driven treadmill at different velocities and constant power output (to test the forced effect of speed) and at power outputs imposed by incline vs. pulley system (to test the effect of method to impose power). Outcome measures were the force and timing variables of the propulsion technique. FEF and timing variables showed significant differences between the speed conditions when propelling at the same power output (p propulsion technique parameters despite an overall constant power output. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Experimental study of surface pattern effects on the propulsive performance and wake of a bio-inspired pitching panel

Science.gov (United States)

King, Justin; Kumar, Rajeev; Green, Melissa

2016-11-01

Force measurements and stereoscopic particle image velocimetry (PIV) were used to characterize the propulsive performance and wake structure of rigid, bio-inspired trapezoidal pitching panels. In the literature, it has been demonstrated that quantities such as thrust coefficient and propulsive efficiency are affected by changes in the surface characteristics of a pitching panel or foil. More specifically, the variation of surface pattern produces significant changes in wake structure and dynamics, especially in the distribution of vorticity in the wake. Force measurements and PIV data were collected for multiple surface patterns chosen to mimic fish surface morphology over a Strouhal number range of 0.17 to 0.56. Performance quantities are compared with the three-dimensional vortex wake structure for both the patterned and smooth panels to determine the nature and magnitude of surface pattern effects in terms of thrust produced, drag reduced, and wake vortices reshaped and reorganized. This work was supported by the Office of Naval Research under ONR Award No. N00014-14-1-0418.

A Comparative Study of Various Electric Propulsion Systems and their Impact on a Nominal Ship Design

Science.gov (United States)

1987-06-01

Permanent Magnet Motors ," Advanced Mechanical Technology, Inc., 1983. 20. Marshall, McMurray, Richter, Webster, and...December 1977. 21. Triezenbarg, Greene, Hannan, and Dvorsky, "Study of Permanent Magnet Motors for Naval Propulsion," Westinghcuse Research Report 80=9B2...34 Paper 71 CP 155-PWR, IEEE Winter Power Meeting, New York, February 1971. 34. Ireland, James R., Ceramic Permanent - Magnet Motors , McGraw-Hill, New York, 1968. 206

The influence of verbal training and visual feedback on manual wheelchair propulsion.

Science.gov (United States)

DeGroot, Keri K; Hollingsworth, Holly H; Morgan, Kerri A; Morris, Carrie L; Gray, David B

2009-03-01

To determine if verbal training with visual feedback improved manual wheelchair propulsion; to examine propulsion differences between an individual with paraplegia and an individual with tetraplegia. Quasi-experimental study: Nine manual wheelchair-using adults participated in propulsion assessments and training. Baseline propulsion performance was measured on several tasks on different surfaces. Participants were trained on a wheelchair treadmill with verbal and visual feedback to increase push length, reduce push frequency and to modify propulsion pattern. Handrim biomechanics were measured with an instrumented wheel. Changes in propulsion were assessed. Differences in propulsion characteristics between a participant with paraplegia and a participant with tetraplegia were examined. Push length increased (p propulsion characteristics between a participant with paraplegia and a participant with tetraplegia. Verbal training may produce changes in push biomechanics of manual wheelchair users. Longer training periods may be needed to sustain propulsion changes. Findings from this study support other studies that have shown propulsion differences between people with tetraplegia and paraplegia. Propulsion training for populations with upper-extremity impairments warrants further study.

Operational experience with propulsion nuclear plants

International Nuclear Information System (INIS)

Polunichev, V.

2000-01-01

Russia possesses a powerful icebreaker transport fleet which offers a solution for important socio-economic tasks of the country's northern regions by maintaining a year-round navigation along the Arctic Sea route. The total operating record of the propulsion nuclear reactors till now exceeds 150 reactor-years, their main equipment items operating life amounted to 120,000 h. Progressive design-constructional solutions being perfected continuously during 40 years of nuclear-powered ships creation in Russia and well proven technology of all components used in the marine nuclear reactors give grounds to recommend marine Nuclear Steam Supply Systems (NSSSs) of KLT-40 type as energy sources for heat and power cogeneration plants and sea water desalination complexes, particularly as floating installations. Co-generation stations are considered for deployment in the extreme north of Russia. Nuclear floating desalination complexes can be used for drinkable water production in coastal regions of Northern Africa, the Near East, India etc. (author)

High-Power Hall Propulsion Development at NASA Glenn Research Center

Science.gov (United States)

Kamhawi, Hani; Manzella, David H.; Smith, Timothy D.; Schmidt, George R.

2014-01-01

The NASA Office of the Chief Technologist Game Changing Division is sponsoring the development and testing of enabling technologies to achieve efficient and reliable human space exploration. High-power solar electric propulsion has been proposed by NASA's Human Exploration Framework Team as an option to achieve these ambitious missions to near Earth objects. NASA Glenn Research Center (NASA Glenn) is leading the development of mission concepts for a solar electric propulsion Technical Demonstration Mission. The mission concepts are highlighted in this paper but are detailed in a companion paper. There are also multiple projects that are developing technologies to support a demonstration mission and are also extensible to NASA's goals of human space exploration. Specifically, the In-Space Propulsion technology development project at NASA Glenn has a number of tasks related to high-power Hall thrusters including performance evaluation of existing Hall thrusters; performing detailed internal discharge chamber, near-field, and far-field plasma measurements; performing detailed physics-based modeling with the NASA Jet Propulsion Laboratory's Hall2De code; performing thermal and structural modeling; and developing high-power efficient discharge modules for power processing. This paper summarizes the various technology development tasks and progress made to date

NASA's nuclear electric propulsion technology project

International Nuclear Information System (INIS)

Stone, J.R.; Sovey, J.S.

1992-07-01

The National Aeronautics and Space Administration (NASA) has initiated a program to establish the readiness of nuclear electric propulsion (NEP) technology for relatively near-term applications to outer planet robotic science missions with potential future evolution to system for piloted Mars vehicles. This program was initiated in 1991 with a very modest effort identified with nuclear thermal propulsion (NTP); however, NEP is also an integral part of this program and builds upon NASA's Base Research and Technology Program in power and electric propulsion as well as the SP-100 space nuclear power program. The NEP Program will establish the feasibility and practicality of electric propulsion for robotic and piloted solar system exploration. The performance objectives are high specific impulse (200 greater than I(sub sp) greater than 10000 s), high efficiency (over 0.50), and low specific mass. The planning for this program was initially focussed on piloted Mars missions, but has since been redirected to first focus on 100-kW class systems for relatively near-term robotic missions, with possible future evolution to megawatt-and multi-megawatt-class systems applicable to cargo vehicles supporting human missions as well as to the piloted vehicles. This paper reviews current plans and recent progress for the overall nuclear electric propulsion project and closely related activities. 33 refs

Integrated controls pay-off. [for flight/propulsion aircraft systems

Science.gov (United States)

Putnam, Terrill W.; Christiansen, Richard S.

1989-01-01

It is shown that the integration of the propulsion and flight control systems for high performance aircraft can help reduce pilot workload while simultaneously increasing overall aircraft performance. Results of the Highly Integrated Digital Electronic Control (HiDEC) flight research program are presented to demonstrate the emerging payoffs of controls integration. Ways in which the performance of fighter aircraft can be improved through the use of propulsion for primary aircraft control are discussed. Research being conducted by NASA with the F-18 High Angle-of Attack Research Vehicle is described.

A comparison of propulsion systems for potential space mission applications

International Nuclear Information System (INIS)

Harvego, E.A.; Sulmeisters, T.K.

1987-01-01

A derivative of the NERVA nuclear rocket engine was compared with a chemical propulsion system and a nuclear electric propulsion system to assess the relative capabilities of the different propulsion system options for three potential space missions. The missions considered were (1) orbital transfer from low earth orbit (LEO) to geosynchronous earth orbit (GEO), (2) LEO to a lunar base, and (3) LEO to Mars. The results of this comparison indicate that the direct-thrust NERVA-derivative nuclear rocket engine has the best performance characteristics for the missions considered. The combined high thrust and high specific impulse achievable with a direct-thrust nuclear stage permits short operating times (transfer times) comparable to chemical propulsion systems, but with considerably less required propellant. While nuclear-electric propulsion systems are more fuel efficient than either direct-nuclear or chemical propulsion, they are not stand-alone systems, since their relatively low thrust levels require the use of high-thrust ferry or lander stages in high gravity applications such as surface-to-orbit propulsion. The extremely long transfer times and inefficient trajectories associated with electric propulsion systems were also found to be a significant drawback

Chemical rocket propulsion a comprehensive survey of energetic materials

CERN Document Server

Shimada, Toru; Sinditskii, Valery; Calabro, Max

2017-01-01

Developed and expanded from the work presented at the New Energetic Materials and Propulsion Techniques for Space Exploration workshop in June 2014, this book contains new scientific results, up-to-date reviews, and inspiring perspectives in a number of areas related to the energetic aspects of chemical rocket propulsion. This collection covers the entire life of energetic materials from their conceptual formulation to practical manufacturing; it includes coverage of theoretical and experimental ballistics, performance properties, as well as laboratory-scale and full system-scale, handling, hazards, environment, ageing, and disposal. Chemical Rocket Propulsion is a unique work, where a selection of accomplished experts from the pioneering era of space propulsion and current technologists from the most advanced international laboratories discuss the future of chemical rocket propulsion for access to, and exploration of, space. It will be of interest to both postgraduate and final-year undergraduate students in...

Nuclear electric propulsion: An integral part of NASA's nuclear propulsion project

International Nuclear Information System (INIS)

Stone, J.R.

1992-01-01

NASA has initiated a technology program to establish the readiness of nuclear propulsion technology for the Space Exploration Initiative (SEI). This program was initiated with a very modest effort identified with nuclear thermal propulsion (NTP); however, nuclear electric propulsion (NEP) is also an integral part of this program and builds upon NASA's Base Research and Technology Program in power and electric propulsion as well as the SP-100 space nuclear power program. Although the Synthesis Group On America's SEI has identified NEP only as an option for cargo missions, recent studies conducted by NASA-Lewis show that NEP offers the potential for early manned Mars missions as well. Lower power NEP is also of current interest for outer planetary robotic missions. Current plans are reviewed for the overall nuclear propulsion project, with emphasis on NEP and those elements of NTP program which have synergism with NEP

Performance of Small Thrusters and Propulsion Systems

Science.gov (United States)

1990-03-01

Van Manen at the Netherlands Ship Model Basin conducted a series of 13 experiments with a variety of nozzles and propellers [Refs. 5, 8]. He...diameter of the screw by about 10 percent. Additionally, van Manen characterized the usefulness of a Kort nozzle in terms of the value of the Taylor...1989. 5. Van Manen , J. D., and Superina, A., "The Design of Screw Pro- pellers in Nozzles," International Shipbuilding Progress, v. 6, no. 55, 1959. 6

Towards Real Time Simulation of Ship-Ship Interaction

DEFF Research Database (Denmark)

Lindberg, Ole; Bingham, Harry B.; Engsig-Karup, Allan Peter

2012-01-01

We present recent and preliminary work directed towards the development of a simplified, physics-based model for improved simulation of ship-ship interaction that can be used for both analysis and real-time computing (i.e. with real-time constraints due to visualization). The goal is to implement...... accurate (realistic) and much faster ship-wave and ship-ship simulations than are currently possible. The coupling of simulation with visualization should improve the visual experience such that it can be perceived as more realistic in training. Today the state-of-art in real-time ship-ship interaction...... is for efficiency reasons and time-constraints in visualization based on model experiments in towing tanks and precomputed force tables. We anticipate that the fast, and highly parallel, algorithm described by Engsig-Karup et al. [2011] for execution on affordable modern high-throughput Graphics Processing Units...

A study of the relationships between quality management practices and organizational performance in the shipping industry

OpenAIRE

T C E Cheng; Petrus W C Choy

2013-01-01

It is generally accepted that firms that pursue sound quality management practices will become more competitive due to enhanced business excellence and performance. However, relatively little research has studied the relationships between quality management practices and organizational performance in the shipping industry. We conduct this study to plug this gap in the literature. We conduct a large-scale industry survey to collect data and develop three measures of organizational performance,...

The Economics of Advanced In-Space Propulsion

Science.gov (United States)

Bangalore, Manju; Dankanich, John

2016-01-01

The cost of access to space is the single biggest driver is commercial space sector. NASA continues to invest in both launch technology and in-space propulsion. Low-cost launch systems combined with advanced in-space propulsion offer the greatest potential market capture. Launch market capture is critical to national security and has a significant impact on domestic space sector revenue. NASA typically focuses on pushing the limits on performance. However, the commercial market is driven by maximum net revenue (profits). In order to maximum the infusion of NASA investments, the impact on net revenue must be known. As demonstrated by Boeing's dual launch, the Falcon 9 combined with all Electric Propulsion (EP) can dramatically shift the launch market from foreign to domestic providers.

Propulsion system research and development for electric and hybrid vehicles

Science.gov (United States)

Schwartz, H. J.

1980-01-01

An approach to propulsion subsystem technology is presented. Various tests of component reliability are described to aid in the production of better quality vehicles. component characterization work is described to provide engineering data to manufacturers on component performance and on important component propulsion system interactions.

Development of An Intelligent Flight Propulsion Control System

Science.gov (United States)

Calise, A. J.; Rysdyk, R. T.; Leonhardt, B. K.

1999-01-01

The initial design and demonstration of an Intelligent Flight Propulsion and Control System (IFPCS) is documented. The design is based on the implementation of a nonlinear adaptive flight control architecture. This initial design of the IFPCS enhances flight safety by using propulsion sources to provide redundancy in flight control. The IFPCS enhances the conventional gain scheduled approach in significant ways: (1) The IFPCS provides a back up flight control system that results in consistent responses over a wide range of unanticipated failures. (2) The IFPCS is applicable to a variety of aircraft models without redesign and,(3) significantly reduces the laborious research and design necessary in a gain scheduled approach. The control augmentation is detailed within an approximate Input-Output Linearization setting. The availability of propulsion only provides two control inputs, symmetric and differential thrust. Earlier Propulsion Control Augmentation (PCA) work performed by NASA provided for a trajectory controller with pilot command input of glidepath and heading. This work is aimed at demonstrating the flexibility of the IFPCS in providing consistency in flying qualities under a variety of failure scenarios. This report documents the initial design phase where propulsion only is used. Results confirm that the engine dynamics and associated hard nonlineaaities result in poor handling qualities at best. However, as demonstrated in simulation, the IFPCS is capable of results similar to the gain scheduled designs of the NASA PCA work. The IFPCS design uses crude estimates of aircraft behaviour. The adaptive control architecture demonstrates robust stability and provides robust performance. In this work, robust stability means that all states, errors, and adaptive parameters remain bounded under a wide class of uncertainties and input and output disturbances. Robust performance is measured in the quality of the tracking. The results demonstrate the flexibility of

Manual wheelchair propulsion patterns on natural surfaces during start-up propulsion.

Science.gov (United States)

Koontz, Alicia M; Roche, Bailey M; Collinger, Jennifer L; Cooper, Rory A; Boninger, Michael L

2009-11-01

To classify propulsion patterns over surfaces encountered in the natural environment during start-up and compare selected biomechanical variables between pattern types. Case series. National Veterans Wheelchair Games, Minneapolis, MN, 2005. Manual wheelchair users (N=29). Subjects pushed their wheelchairs from a resting position over high-pile carpet, over linoleum, and up a ramp with a 5 degrees incline while propulsion kinematics and kinetics were recorded with a motion capture system and an instrumented wheel. Three raters classified the first 3 strokes as 1 of 4 types on each surface: arc, semicircular (SC), single looping over propulsion (SL), and double looping over propulsion (DL). The Fisher exact test was used to assess pattern changes between strokes and surface type. A multiple analysis of variance test was used to compare peak and average resultant force and moment about the hub, average wheel velocity, stroke frequency, contact angle, and distance traveled between stroke patterns. SL was the most common pattern used during start-up propulsion (44.9%), followed by arc (35.9%), DL (14.1%), and SC (5.1%). Subjects who dropped their hands below the rim during recovery achieved faster velocities and covered greater distances (.016propulsion patterns is a difficult task that should use multiple raters. In addition, propulsion patterns change during start-up, with an arc pattern most prevalent initially. The biomechanical findings in this study agree with current clinical guidelines that recommend training users to drop the hand below the pushrim during recovery.

Evaluation of the use of on-board spacecraft energy storage for electric propulsion missions

Science.gov (United States)

Poeschel, R. L.; Palmer, F. M.

1983-01-01

On-board spacecraft energy storage represents an under utilized resource for some types of missions that also benefit from using relatively high specific impulse capability of electric propulsion. This resource can provide an appreciable fraction of the power required for operating the electric propulsion subsystem in some missions. The most probable mission requirement for utilization of this energy is that of geostationary satellites which have secondary batteries for operating at high power levels during eclipse. The study summarized in this report selected four examples of missions that could benefit from use of electric propulsion and on-board energy storage. Engineering analyses were performed to evaluate the mass saved and economic benefit expected when electric propulsion and on-board batteries perform some propulsion maneuvers that would conventionally be provided by chemical propulsion. For a given payload mass in geosynchronous orbit, use of electric propulsion in this manner typically provides a 10% reduction in spacecraft mass.

Overview of solutions and analysis of the ability to evaluate the performance parameters of unmanned aerial vehicles propulsion systems

Directory of Open Access Journals (Sweden)

Karpiński Dominik

2017-01-01

Full Text Available The aim of aircraft engines development is the propulsion which is characterized by high power-to-mass ratio. Therefore, the alternative solutions that provide the required power by the low weight propulsion are sought after. The main advantage of these solutions is improvement of environmental and economic properties. This paper presents the overview of solutions and studies conducted for the unmanned aerial vehicles propulsion. For the purposes of studies a test bench was prepared. Its enables the comparison of the propulsion operating parameters taking into account changes in the values of thrust and propulsion power. The summary includes a proposal to improve the environmental indicators of propulsion systems for unmanned aerial vehicles.

Advanced propulsion system for hybrid vehicles

Science.gov (United States)

Norrup, L. V.; Lintz, A. T.

1980-01-01

A number of hybrid propulsion systems were evaluated for application in several different vehicle sizes. A conceptual design was prepared for the most promising configuration. Various system configurations were parametrically evaluated and compared, design tradeoffs performed, and a conceptual design produced. Fifteen vehicle/propulsion systems concepts were parametrically evaluated to select two systems and one vehicle for detailed design tradeoff studies. A single hybrid propulsion system concept and vehicle (five passenger family sedan)were selected for optimization based on the results of the tradeoff studies. The final propulsion system consists of a 65 kW spark-ignition heat engine, a mechanical continuously variable traction transmission, a 20 kW permanent magnet axial-gap traction motor, a variable frequency inverter, a 386 kg lead-acid improved state-of-the-art battery, and a transaxle. The system was configured with a parallel power path between the heat engine and battery. It has two automatic operational modes: electric mode and heat engine mode. Power is always shared between the heat engine and battery during acceleration periods. In both modes, regenerative braking energy is absorbed by the battery.

The shipping man adventures in ship finance

CERN Document Server

McCleery, Matthew

2013-01-01

When restless New York City hedge fund manager Robert Fairchild watches the Baltic Dry Cargo Index plunge 97%, registering an all-time high and a 25-year low within the span of just six months, he decides to buy a ship. Immediately fantasizing about naming a vessel after his wife, carrying a string of worry beads and being able to introduce himself as a "shipowner" at his upcoming college reunion, Fairchild immediately embarks on an odyssey into the most exclusive, glamorous and high stakes business in the world. From pirates off the coast of Somalia and on Wall Street to Greek and Norwegian shipping magnates, the education of Robert Fairchild is an expensive one. In the end, he loses his hedge fund, but he gains a life - as a Shipping Man. Part fast paced financial thriller, part ship finance text book, The Shipping Man is 310 pages of required reading for anyone with an interest in capital formation for shipping.

A summary of EHV propulsion technology. [Electric and Hybrid Vehicle

Science.gov (United States)

Schwartz, H. J.

1983-01-01

While the battery used by an electric vehicle is the primary determinant of range, and to a lesser extent of performance, the design of the vehicle's propulsion system establishes its performance level and is the greatest contributor to its purchase price. Propulsion system weight, efficiency and cost are related to the specific combination of components used. Attention is given to the development status of the U.S. Department of Energy's Electric and Hybrid Vehicle Program, through which propulsion component and system design improvements have been made which promise weight savings of 35-50 percent, efficiency gains of 25 percent, and lower costs, when compared to the state of the art at the program's inception.

Are nuclear ships environmentally safer than conventionally powered ships

International Nuclear Information System (INIS)

Bone, C.A.; Molgaard, C.A.; Helmkamp, J.C.; Golbeck, A.L.

1988-01-01

An epidemiologic analysis was conducted to determine if risk of hospitalization varied by age, ship type, or occupation between nuclear and conventional powered ship crews in the U.S. Navy. Study cohorts consisted of all male enlisted personnel who served exclusively aboard conventional or nuclear powered aircraft carriers and cruisers during the years 1975-1979; cases were those men hospitalized during this period (N = 48,242). Conventional ship personnel showed significantly elevated rates of injury and disease when compared to nuclear ship personnel. The largest relative risks by age occurred for conventional ship crewmen less than 30 years old. Seaman, logistics (supply), and healthcare personnel serving aboard conventional ships comprised the occupational groups exhibiting the highest hospitalization rate differentials. The results strongly suggest that nuclear ships provide a healthier, safer working and living environment than conventional ships

Shipping

NARCIS (Netherlands)

Wijnolst, N.; Wergeland, T.

1996-01-01

Shipping is a multi-faceted industry which is rather complex to define from an academic point of view. This book attempts to grasp these complexities and provide the reader with an overview of the main topics and terminology in shipping. The book is based on material from our courses in shipping at

Re-evaluation of the criticality experiments of the ''Otto Hahn Nuclear Ship'' reactor

Energy Technology Data Exchange (ETDEWEB)

Lengar, I.; Snoj, L.; Rogan, P.; Ravnik, M. [Jozef Stefan Institute, Ljubljana (Slovenia)

2008-11-15

Several series of experiments with a FDR reactor (advanced pressurized light water reactor) were performed in 1972 in the Geesthacht critical facility ANEX. The experiments were performed to test the core prior to its usage for the propulsion of the first German nuclear merchant ship ''Otto-Hahn''. In the present paper a calculational re-evaluation of the experiments is described with the use of the up-to date computer codes (Monte-Carlo code MCNP5) and nuclear data (ENDF/B-VI release 6). It is focused on the determination of uncertainties in the benchmark model of the experimental set-up, originating mainly from the limited set of information still available about the experiments. Effects of the identified uncertainties on the multiplication factor were studied. The sensitivity studies include parametric variation of material composition and geometry. The combined total uncertainty being found 0.0050 in k{sub eff}, the experiments are qualified as criticality safety benchmark experiments. (orig.)

28th Joint Propulsion Conference and Exhibit

International Nuclear Information System (INIS)

Stone, J.R.; Sovey, J.S.

1992-07-01

The National Aeronautics and Space Administration (NASA) has initiated a program to establish the readiness of nuclear electric propulsion (NEP) technology for relatively near-term applications to outer planet robotic science missions with potential future evolution to system for piloted Mars vehicles. This program was initiated in 1991 with a very modest effort identified with nuclear thermal propulsion (NTP); however, NEP is also an integral part of this program and builds upon NASA's Base Research and Technology Program in power and electric propulsion as well as the SP-100 space nuclear power program. The NEP Program will establish the feasibility and practicality of electric propulsion for robotic and piloted solar system exploration. The performance objectives are high specific impulse (200 greater than I(sub sp) greater than 10000 s), high efficiency (over 0.50), and low specific mass. The planning for this program was initially focussed on piloted Mars missions, but has since been redirected to first focus on 100-kW class systems for relatively near-term robotic missions, with possible future evolution to megawatt- and multi-megawatt-class systems applicable to cargo vehicles supporting human missions as well as to the piloted vehicles. This paper reviews current plans and recent progress for the overall nuclear electric propulsion project and closely related activities

ERDC Ship/Tow Simulator

Data.gov (United States)

Federal Laboratory Consortium — Performing Advanced Hydrodynamic ModelingEngineers and ship pilots can now overcome the challenges of evaluating navigation channel designs, modifications and safety...

LANDSAT/MMS propulsion module design. Tas4.4: Concept design

Science.gov (United States)

Mansfield, J. M.; Etheridge, F. G.; Indrikis, J.

1976-01-01

Evaluations are presented of alternative LANDSAT follow-on launch configurations to derive the propulsion requirements for the multimission modular spacecraft (MMS). Two basic types were analyzed including use of conventional launch vehicles and shuttle supported missions. It was concluded that two sizes of modular hydrazine propulsion modules would provide the most cost-effective combination for future missions of this spacecraft. Conceptual designs of the selected propulsion modules were performed to the depth permitting determination of mass properties and estimated costs.

Numerical Propulsion System Simulation (NPSS): An Award Winning Propulsion System Simulation Tool

Science.gov (United States)

Stauber, Laurel J.; Naiman, Cynthia G.

2002-01-01

The Numerical Propulsion System Simulation (NPSS) is a full propulsion system simulation tool used by aerospace engineers to predict and analyze the aerothermodynamic behavior of commercial jet aircraft, military applications, and space transportation. The NPSS framework was developed to support aerospace, but other applications are already leveraging the initial capabilities, such as aviation safety, ground-based power, and alternative energy conversion devices such as fuel cells. By using the framework and developing the necessary components, future applications that NPSS could support include nuclear power, water treatment, biomedicine, chemical processing, and marine propulsion. NPSS will dramatically reduce the time, effort, and expense necessary to design and test jet engines. It accomplishes that by generating sophisticated computer simulations of an aerospace object or system, thus enabling engineers to "test" various design options without having to conduct costly, time-consuming real-life tests. The ultimate goal of NPSS is to create a numerical "test cell" that enables engineers to create complete engine simulations overnight on cost-effective computing platforms. Using NPSS, engine designers will be able to analyze different parts of the engine simultaneously, perform different types of analysis simultaneously (e.g., aerodynamic and structural), and perform analysis in a more efficient and less costly manner. NPSS will cut the development time of a new engine in half, from 10 years to 5 years. And NPSS will have a similar effect on the cost of development: new jet engines will cost about a billion dollars to develop rather than two billion. NPSS is also being applied to the development of space transportation technologies, and it is expected that similar efficiencies and cost savings will result. Advancements of NPSS in fiscal year 2001 included enhancing the NPSS Developer's Kit to easily integrate external components of varying fidelities, providing

Wavelet-based information filtering for fault diagnosis of electric drive systems in electric ships.

Science.gov (United States)

Silva, Andre A; Gupta, Shalabh; Bazzi, Ali M; Ulatowski, Arthur

2017-09-22

Electric machines and drives have enjoyed extensive applications in the field of electric vehicles (e.g., electric ships, boats, cars, and underwater vessels) due to their ease of scalability and wide range of operating conditions. This stems from their ability to generate the desired torque and power levels for propulsion under various external load conditions. However, as with the most electrical systems, the electric drives are prone to component failures that can degrade their performance, reduce the efficiency, and require expensive maintenance. Therefore, for safe and reliable operation of electric vehicles, there is a need for automated early diagnostics of critical failures such as broken rotor bars and electrical phase failures. In this regard, this paper presents a fault diagnosis methodology for electric drives in electric ships. This methodology utilizes the two-dimensional, i.e. scale-shift, wavelet transform of the sensor data to filter optimal information-rich regions which can enhance the diagnosis accuracy as well as reduce the computational complexity of the classifier. The methodology was tested on sensor data generated from an experimentally validated simulation model of electric drives under various cruising speed conditions. The results in comparison with other existing techniques show a high correct classification rate with low false alarm and miss detection rates. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

On the Global Ship Hull Bending Energy in Ship Collisions

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Li, Y.

2004-01-01

During ship collisions part of the kinetic energy of the involved vessels prior to contact is absorbed as energy dissipated by crushing of the hull structures, by friction and by elastic energy. The purpose of this report is to present an estimate of the elastic energy that can be stored in elastic...... hull vibrations during a ship collision. When a ship side is strengthened in order to improve the crashworthiness it has been argued in the scientific literature that a non trivial part of the energy released for structural deformation during the collision can be absorbed as elastic energy in global...... ship hull vibrations, such that with strong ship sides less energy has to be spent in crushing of the striking ship bow and/or the struck ship side. In normal ship-ship collision analyses both the striking and struck ship are usually considered as rigid bodies where structural crushing is confined...

Coefficients of Propeller-hull Interaction in Propulsion System of Inland Waterway Vessels with Stern Tunnels

Directory of Open Access Journals (Sweden)

Jan Kulczyk

2014-09-01

Full Text Available Propeller-hull interaction coefficients - the wake fraction and the thrust deduction factor - play significant role in design of propulsion system of a ship. In the case of inland waterway vessels the reliable method of predicting these coefficients in early design stage is missing. Based on the outcomes from model tests and from numerical computations the present authors show that it is difficult to determine uniquely the trends in change of wake fraction and thrust deduction factor resulting from the changes of hull form or operating conditions. Nowadays the resistance and propulsion model tests of inland waterway vessels are carried out rarely because of relatively high costs. On the other hand, the degree of development of computational methods enables’ to estimate the reliable values o interaction coefficients. The computations referred to in the present paper were carried out using the authors’ own software HPSDKS and the commercial software Ansys Fluent.

Swimming mechanics and propulsive efficiency in the chambered nautilus

Science.gov (United States)

Neil, Thomas R.; Askew, Graham N.

2018-02-01

The chambered nautilus (Nautilus pompilius) encounters severe environmental hypoxia during diurnal vertical movements in the ocean. The metabolic cost of locomotion (Cmet) and swimming performance depend on how efficiently momentum is imparted to the water and how long on-board oxygen stores last. While propulsive efficiency is generally thought to be relatively low in jet propelled animals, the low Cmet in Nautilus indicates that this is not the case. We measured the wake structure in Nautilus during jet propulsion swimming, to determine their propulsive efficiency. Animals swam with either an anterior-first or posterior-first orientation. With increasing swimming speed, whole cycle propulsive efficiency increased during posterior-first swimming but decreased during anterior-first swimming, reaching a maximum of 0.76. The highest propulsive efficiencies were achieved by using an asymmetrical contractile cycle in which the fluid ejection phase was relatively longer than the refilling phase, reducing the volume flow rate of the ejected fluid. Our results demonstrate that a relatively high whole cycle propulsive efficiency underlies the low Cmet in Nautilus, representing a strategy to reduce the metabolic demands in an animal that spends a significant part of its daily life in a hypoxic environment.

Hybrid rocket propulsion systems for outer planet exploration missions

Science.gov (United States)

Jens, Elizabeth T.; Cantwell, Brian J.; Hubbard, G. Scott

2016-11-01

Outer planet exploration missions require significant propulsive capability, particularly to achieve orbit insertion. Missions to explore the moons of outer planets place even more demanding requirements on propulsion systems, since they involve multiple large ΔV maneuvers. Hybrid rockets present a favorable alternative to conventional propulsion systems for many of these missions. They typically enjoy higher specific impulse than solids, can be throttled, stopped/restarted, and have more flexibility in their packaging configuration. Hybrids are more compact and easier to throttle than liquids and have similar performance levels. In order to investigate the suitability of these propulsion systems for exploration missions, this paper presents novel hybrid motor designs for two interplanetary missions. Hybrid propulsion systems for missions to Europa and Uranus are presented and compared to conventional in-space propulsion systems. The hybrid motor design for each of these missions is optimized across a range of parameters, including propellant selection, O/F ratio, nozzle area ratio, and chamber pressure. Details of the design process are described in order to provide guidance for researchers wishing to evaluate hybrid rocket motor designs for other missions and applications.

The USAF Electric Propulsion Program

National Research Council Canada - National Science Library

Spores, Ronald

1999-01-01

...: Propulsion Directorate and Air Force Office of Scientific Research (AFOSR). The Propulsion Directorate conducts electric propulsion efforts in basic research, engineering development, and space experiments...

Advanced Propulsion Study

National Research Council Canada - National Science Library

Davis, Eric

2004-01-01

... that show promise of leading to a major advance in Earth-to-orbit (ETO) propulsion. The study also reviewed and evaluated a select number of credible far-term breakthrough propulsion physics concepts pertaining...

NASA's Propulsion Research Laboratory

Science.gov (United States)

2004-01-01

The grand opening of NASA's new, world-class laboratory for research into future space transportation technologies located at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama, took place in July 2004. The state-of-the-art Propulsion Research Laboratory (PRL) serves as a leading national resource for advanced space propulsion research. Its purpose is to conduct research that will lead to the creation and development of innovative propulsion technologies for space exploration. The facility is the epicenter of the effort to move the U.S. space program beyond the confines of conventional chemical propulsion into an era of greatly improved access to space and rapid transit throughout the solar system. The laboratory is designed to accommodate researchers from across the United States, including scientists and engineers from NASA, the Department of Defense, the Department of Energy, universities, and industry. The facility, with 66,000 square feet of useable laboratory space, features a high degree of experimental capability. Its flexibility allows it to address a broad range of propulsion technologies and concepts, such as plasma, electromagnetic, thermodynamic, and propellant propulsion. An important area of emphasis is the development and utilization of advanced energy sources, including highly energetic chemical reactions, solar energy, and processes based on fission, fusion, and antimatter. The Propulsion Research Laboratory is vital for developing the advanced propulsion technologies needed to open up the space frontier, and sets the stage of research that could revolutionize space transportation for a broad range of applications.

An N+3 Technology Level Reference Propulsion System

Science.gov (United States)

Jones, Scott M.; Haller, William J.; Tong, Michael To-Hing

2017-01-01

An N+3 technology level engine, suitable as a propulsion system for an advanced single-aisle transport, was developed as a reference cycle for use in technology assessment and decision-making efforts. This reference engine serves three main purposes: it provides thermodynamic quantities at each major engine station, it provides overall propulsion system performance data for vehicle designers to use in their analyses, and it can be used for comparison against other proposed N+3 technology-level propulsion systems on an equal basis. This reference cycle is meant to represent the expected capability of gas turbine engines in the N+3 timeframe given reasonable extrapolations of technology improvements and the ability to take full advantage of those improvements.

Investigation of Various Novel Air-Breathing Propulsion Systems

Science.gov (United States)

Wilhite, Jarred M.

The current research investigates the operation and performance of various air-breathing propulsion systems, which are capable of utilizing different types of fuel. This study first focuses on a modular RDE configuration, which was mainly studied to determine which conditions yield stable, continuous rotating detonation for an ethylene-air mixture. The performance of this RDE was analyzed by studying various parameters such as mass flow rate, equivalence ratios, wave speed and cell size. For relatively low mass flow rates near stoichiometric conditions, a rotating detonation wave is observed for an ethylene-RDE, but at speeds less than an ideal detonation wave. The current research also involves investigating the newly designed, Twin Oxidizer Injection Capable (TOXIC) RDE. Mixtures of hydrogen and air were utilized for this configuration, resulting in sustained rotating detonation for various mass flow rates and equivalence ratios. A thrust stand was also developed to observe and further measure the performance of the TOXIC RDE. Further analysis was conducted to accurately model and simulate the response of thrust stand during operation of the RDE. Also included in this research are findings and analysis of a propulsion system capable of operating on the Inverse Brayton Cycle. The feasibility of this novel concept was validated in a previous study to be sufficient for small-scale propulsion systems, namely UAV applications. This type of propulsion system consists of a reorganization of traditional gas turbine engine components, which incorporates expansion before compression. This cycle also requires a heat exchanger to reduce the temperature of the flow entering the compressor downstream. While adding a heat exchanger improves the efficiency of the cycle, it also increases the engine weight, resulting in less endurance for the aircraft. Therefore, this study focuses on the selection and development of a new heat exchanger design that is lightweight, and is capable

Propulsive efficiency of a biomorphic pulsed-jet underwater vehicle

International Nuclear Information System (INIS)

Moslemi, Ali A; Krueger, Paul S

2010-01-01

The effect of the velocity program and duty cycle (St L ) on the propulsive efficiency of pulsed-jet propulsion was studied experimentally on a self-propelled, pulsed-jet underwater vehicle, dubbed Robosquid due to the similarity of essential elements of its propulsion system with squid jet propulsion. Robosquid was tested for jet slug length-to-diameter ratios (L/D) in the range 2-6 and St L in the range 0.2-0.6 with jet velocity programs commanded to be triangular or trapezoidal. Digital particle image velocimetry was used for measuring the impulse and energy of jet pulses to calculate the pulsed-jet propulsive efficiency and compare it with an equivalent steady jet system. Robosquid's Reynolds number (Re) based on average vehicle velocity and vehicle diameter ranged between 1300 and 2700 for the conditions tested. The results indicated better propulsive efficiency of the trapezoidal velocity program (up to 20% higher) compared to the triangular velocity program. Also, an increase in the ratio of the pulsed-jet propulsive efficiency to the equivalent steady jet propulsive efficiency (η P /η P,ss ) was observed as St L increased and L/D decreased. For cases of short L/D and high St L , η P /η P,ss was found to be as high as 1.2, indicating better performance of pulsed jets. This result demonstrates a case where propulsion using essential elements of a biological locomotion system can outperform the traditional mechanical system equivalent in terms of efficiency. It was also found that changes in St L had a proportionately larger effect on propulsive efficiency compared to changes in L/D. A simple model is presented to explain the results in terms of the contribution of over-pressure at the nozzle exit plane associated with the formation of vortex rings with each jet pulse.

Fin Ray Stiffness and Fin Morphology Control Ribbon-Fin-Based Propulsion.

Science.gov (United States)

Liu, Hanlin; Taylor, Bevan; Curet, Oscar M

2017-06-01

Ribbon-fin-based propulsion has rich locomotor capabilities that can enhance the mobility and performance of underwater vehicles navigating in complex environments. Bony fishes using this type of propulsion send one or multiple traveling waves along an elongated fin with the actuation of highly flexible rays that are interconnected by an elastic membrane. In this work, we study how the use of flexible rays and different morphology can affect the performance of ribbon-fin propulsion. We developed a physical model composed of 15 rays that are interconnected with an elastic membrane. We tested four different ray flexural stiffness and four aspect ratios. The robotic model was tested in a low-turbulence flume under two flow conditions ([Formula: see text] wavelength/s). In two experimental sets, we measured fin kinematics, net surge forces, and power consumption. Using these data, we perform a thrust and power analysis of the undulating fin. We present the thrust coefficient, power coefficient, and propulsive efficiency. We find that the thrust generation was linear with the enclosed area swept by the fin, and square of the relative velocity between the incoming flow and traveling wave. The thrust coefficient levels off around 0.5. In addition, for our parameter range, we find that the power consumption scales by the cube of the effective tangential velocity of the rays [Formula: see text] (A is the amplitude of the ray oscillating motion, and [Formula: see text] is the angular velocity). We show that a decay in stiffness decreases both thrust production and power consumption. However, for rays with high flexural stiffness, the difference in thrust compared with rigid rays is minimal. Moreover, our results show that flexible rays can improve the propulsive efficiency compared with a rigid counterpart. Finally, we find that the morphology of ribbon fin affects its propulsive efficiency. For the aspect ratio considered in our experiments, [Formula: see text] was the most

The NASA In-Space Propulsion Technology Project, Products, and Mission Applicability

Science.gov (United States)

Anderson, David J.; Pencil, Eric; Liou, Larry; Dankanich, John; Munk, Michelle M.; Kremic, Tibor

2009-01-01

The In-Space Propulsion Technology (ISPT) Project, funded by NASA s Science Mission Directorate (SMD), is continuing to invest in propulsion technologies that will enable or enhance NASA robotic science missions. This overview provides development status, near-term mission benefits, applicability, and availability of in-space propulsion technologies in the areas of aerocapture, electric propulsion, advanced chemical thrusters, and systems analysis tools. Aerocapture investments improved: guidance, navigation, and control models of blunt-body rigid aeroshells; atmospheric models for Earth, Titan, Mars, and Venus; and models for aerothermal effects. Investments in electric propulsion technologies focused on completing NASA s Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6 to 7 kW throttle-able gridded ion system. The project is also concluding its High Voltage Hall Accelerator (HiVHAC) mid-term product specifically designed for a low-cost electric propulsion option. The primary chemical propulsion investment is on the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. The project is also delivering products to assist technology infusion and quantify mission applicability and benefits through mission analysis and tools. In-space propulsion technologies are applicable, and potentially enabling for flagship destinations currently under evaluation, as well as having broad applicability to future Discovery and New Frontiers mission solicitations.

On the global ship hull bending energy in ship collisions

DEFF Research Database (Denmark)

Pedersen, Preben Terndrup; Li, Yujie

2009-01-01

During ship collisions part of the kinetic energy of the involved vessels immediately prior to contact is absorbed as energy dissipated by crushing of the hull structures, by friction and by elastic energy. The purpose of this report is to present an estimate of the elastic energy that can...... be stored in elastic hull vibrations during a ship collision. When a ship side is strengthened in order to improve the crashworthiness it has been argued in the scientific literature that a non-trivial part of the energy released for structural deformation during the collision can be absorbed as elastic...... energy in global ship hull vibrations, such that with strong ship sides less energy has to be spent in crushing of the striking ship bow and/or the struck ship side. In normal ship–ship collision analyses both the striking and struck ship are usually considered as rigid bodies where structural crushing...

The use of engineering features and schematic solutions of propulsion nuclear steam supply systems for floating nuclear power plant design

International Nuclear Information System (INIS)

Achkasov, A.N.; Grechko, G.I.; Pepa, V.N.; Shishkin, V.A.

2000-01-01

In recent years many countries and the international community represented by the IAEA have shown a notable interest in designing small and medium size nuclear power plants intended for electricity and heat generation for remote areas. These power plants can be also used for desalination purposes. As these nuclear plants are planned for use in areas without a well-developed power grid, the design shall account for their transportation to the site in complete preparedness for operation. Since the late 80s, the Research and Development Institute of Power Engineering (RDIPE) has carried out active efforts in designing reactor facilities for floating nuclear power plants. This work relies on the long-term experience of RDIPE engineers in designing the propulsion NSSS. Advantages can be gained from the specific engineering solutions that are already applied in the design of propulsion Nuclear Steam Supply System (NSSS) or from development of new designs based on the proven technologies. Successful implementation of the experience has been made easier owing to rather similar design requirements prescribed to ship-mounted NSSS and floating NPP. The common design targets are, in particular, minimization of mass and dimensions, resistance to such external impacts as rolling, heel and trim, operability in case of running aground or collision with other ships, etc. (author)

Effects of synchronous versus asynchronous mode of propulsion on wheelchair basketball sprinting.

Science.gov (United States)

Faupin, Arnaud; Borel, Benoit; Meyer, Christophe; Gorce, Philippe; Watelain, Eric

2013-11-01

This study aimed to first investigate synchronous (SYN) versus asynchronous (ASY) mode of propulsion and, second, investigate the wheel camber effects on sprinting performance as well as temporal parameters. Seven wheelchair basketball players performed four maximal eight-second sprints on a wheelchair ergometer. They repeated the test according to two modes of propulsion (SYN and ASY) and two wheel cambers (9° and 15°). The mean maximal velocity and push power output was greater in the synchronous mode compared to the asynchronous mode for both camber angles. However, the fluctuation in the velocity profile is inferior for ASY versus SYN mode for both camber angles. Greater push time/cycle time (Pt/Ct) and arm frequency (AF) for synchronous mode versus asynchronous mode and inversely, lesser Ct and rest time (Rt) values for the synchronous mode, for which greater velocity were observed. SYN mode leads to better performance than ASY mode in terms of maximal propulsion velocity. However, ASY propulsion allows greater continuity of the hand-rim force application, reducing fluctuations in the velocity profile. The camber angle had no effect on ASY and SYN mean maximal velocity and push power output. The study of wheelchair propulsion strategies is important for better understanding physiological and biomechanical impacts of wheelchair propulsion for individuals with disabilities. From a kinematical point of view, this study highlights synchronous mode of propulsion to be more efficient, with regards to mean maximal velocity reaching during maximal sprinting exercises. Even if this study focuses on well-trained wheelchair athletes, results from this study could complement the knowledge on the physiological and biomechanical adaptations to wheelchair propulsion and therefore, might be interesting for wheelchair modifications for purposes of rehabilitation.

Free-surface flow around an appended hull

International Nuclear Information System (INIS)

Lungu, A; Pacuraru, F

2010-01-01

The prediction of the total drag experienced by an advancing ship is a complicated problem which requires a thorough understanding of the hydrodynamic forces acting on the hull, the physical processes from which these forces arise as well as their mutual interaction. A general numerical method to predict the hydrodynamic performance of a twin-propeller combatant ship is presented in the paper, which describes the solution of a RANS solver coupled with a body force method as an attempt in investigating the flow features around the ship hull equipped with rotating propellers and rudders. A special focus is made on the propeller non-symmetrical inflow field, aimed at obtaining the necessary data for the propulsive performances evaluation as well as for the propeller final design. The reported work allows not only the performance evaluation for the overall performances of a hull, but also leads to the development, implementation and validation of new concepts in modeling the turbulent vortical flows, with direct connection to the ship propulsion problem.

An experimental investigation of the performance of metallic and sandwich ship bulkheads under combined thermo-mechanical loading

DEFF Research Database (Denmark)

Karatzas, Vasileios; Lauridsen, Dan; Berggreen, Christian

using metallic materials despite the fact that these lead to heavy designs, and they are susceptible to corrosion and fatigue. The reason why composites have not been implemented in commercial shipping is because until 2002, when the so-called regulation 17 was introduced, SOLAS regulations did...... not allow the use of combustible materials onboard ships [1]. Nevertheless this rule has proven hard to implement as the evaluation and acceptance of designs encompassing composite materials has proven cumber-some. Moreover, the existing set of regulations were introduced at a time when metallic materials...... were the sole option and as such they do not explicitly address issues related to the performance of com-posite materials but rather try to enforce the same operational criteria that exist for metallic structures to their composite counterparts. The scope of this work is to compare the performance...

An Overview of the CNES Propulsion Program for Spacecraft

Science.gov (United States)

Cadiou, A.; Darnon, F.; Gibek, I.; Jolivet, L.; Pillet, N.

2004-10-01

This paper presents an overview of the CNES spacecraft propulsion activities. The main existing and future projects corresponding to low earth orbit and geostationary platforms are described. These projects cover various types of propulsion subsystems: monopropellant, bipropellant and electric. Monopropellant is mainly used for low earth orbit applications such as earth observation (SPOT/Helios, PLEIADES) or scientific applications (minisatellite PROTEUS line and micro satellites MYRIADE line). Bipropellant is used for geostationary telecommunications satellites (@BUS). The field of application of electric propulsion is the station keeping of geostationary telecommunication satellites (@BUS), main propulsion for specific probes (SMART 1) and fine attitude control for dedicated micro satellites (MICROSCOPE). The preparation of the future and the associated Research and Technology program are also described in the paper. The future developments are mainly dedicated to the performance improvements of electric propulsion which leads to the development of thrusters with higher thrust and higher specific impulse than those existing today, the evaluation of the different low thrust technologies for formation flying applications, the development of new systems to pressurize the propellants (volatile liquid, micro pump), the research on green propellants and different actions concerning components such as over wrapped pressure vessels, valves, micro propulsion. A constant effort is also put on plume effect in chemical and electrical propulsion area (improvement of tools and test activities) in the continuity of the previous work. These different R &T activities are described in detail after a presentation of the different projects and of their propulsion subsystems. The scientific activity supporting the development of Hall thrusters is going on in the frame of the GDR (Groupement de Recherche) CNRS / Universities / CNES / SNECMA on Plasma Propulsion.

Recent advances in nuclear powered electric propulsion for space exploration

International Nuclear Information System (INIS)

Cassady, R. Joseph; Frisbee, Robert H.; Gilland, James H.; Houts, Michael G.; LaPointe, Michael R.; Maresse-Reading, Colleen M.; Oleson, Steven R.; Polk, James E.; Russell, Derrek; Sengupta, Anita

2008-01-01

Nuclear and radioisotope powered electric thrusters are being developed as primary in space propulsion systems for potential future robotic and piloted space missions. Possible applications for high-power nuclear electric propulsion include orbit raising and maneuvering of large space platforms, lunar and Mars cargo transport, asteroid rendezvous and sample return, and robotic and piloted planetary missions, while lower power radioisotope electric propulsion could significantly enhance or enable some future robotic deep space science missions. This paper provides an overview of recent US high-power electric thruster research programs, describing the operating principles, challenges, and status of each technology. Mission analysis is presented that compares the benefits and performance of each thruster type for high priority NASA missions. The status of space nuclear power systems for high-power electric propulsion is presented. The paper concludes with a discussion of power and thruster development strategies for future radioisotope electric propulsion systems

Recent advances in nuclear powered electric propulsion for space exploration

Energy Technology Data Exchange (ETDEWEB)

Cassady, R. Joseph [Aerojet Corp., Redmond, CA (United States); Frisbee, Robert H. [Jet Propulsion Laboratory, Pasadena, CA (United States); Gilland, James H. [Ohio Aerospace Institute, Cleveland, OH (United States); Houts, Michael G. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States); LaPointe, Michael R. [NASA Marshall Space Flight Center, Huntsville, AL 35812 (United States)], E-mail: michael.r.lapointe@nasa.gov; Maresse-Reading, Colleen M. [Jet Propulsion Laboratory, Pasadena, CA (United States); Oleson, Steven R. [NASA Glenn Research Center, Cleveland, OH (United States); Polk, James E. [Jet Propulsion Laboratory, Pasadena, CA (United States); Russell, Derrek [Northrop Grumman Space Technology, Redondo Beach, CA (United States); Sengupta, Anita [Jet Propulsion Laboratory, Pasadena, CA (United States)

2008-03-15

Nuclear and radioisotope powered electric thrusters are being developed as primary in space propulsion systems for potential future robotic and piloted space missions. Possible applications for high-power nuclear electric propulsion include orbit raising and maneuvering of large space platforms, lunar and Mars cargo transport, asteroid rendezvous and sample return, and robotic and piloted planetary missions, while lower power radioisotope electric propulsion could significantly enhance or enable some future robotic deep space science missions. This paper provides an overview of recent US high-power electric thruster research programs, describing the operating principles, challenges, and status of each technology. Mission analysis is presented that compares the benefits and performance of each thruster type for high priority NASA missions. The status of space nuclear power systems for high-power electric propulsion is presented. The paper concludes with a discussion of power and thruster development strategies for future radioisotope electric propulsion systems.

Power processing for electric propulsion

Science.gov (United States)

Finke, R. C.; Herron, B. G.; Gant, G. D.

1975-01-01

The potential of achieving up to 30 per cent more spacecraft payload or 50 per cent more useful operating life by the use of electric propulsion in place of conventional cold gas or hydrazine systems in science, communications, and earth applications spacecraft is a compelling reason to consider the inclusion of electric thruster systems in new spacecraft design. The propulsion requirements of such spacecraft dictate a wide range of thruster power levels and operational lifetimes, which must be matched by lightweight, efficient, and reliable thruster power processing systems. This paper will present electron bombardment ion thruster requirements; review the performance characteristics of present power processing systems; discuss design philosophies and alternatives in areas such as inverter type, arc protection, and control methods; and project future performance potentials for meeting goals in the areas of power processor weight (10 kg/kW), efficiency (approaching 92 per cent), reliability (0.96 for 15,000 hr), and thermal control capability (0.3 to 5 AU).

Rocket propulsion elements - An introduction to the engineering of rockets (6th revised and enlarged edition)

Science.gov (United States)

Sutton, George P.

The subject of rocket propulsion is treated with emphasis on the basic technology, performance, and design rationale. Attention is given to definitions and fundamentals, nozzle theory and thermodynamic relations, heat transfer, flight performance, chemical rocket propellant performance analysis, and liquid propellant rocket engine fundamentals. The discussion also covers solid propellant rocket fundamentals, hybrid propellant rockets, thrust vector control, selection of rocket propulsion systems, electric propulsion, and rocket testing.

Compensation of Wave-Induced Motion and Force Phenomena for Ship-Based High Performance Robotic and Human Amplifying Systems

Energy Technology Data Exchange (ETDEWEB)

Love, LJL

2003-09-24

The decrease in manpower and increase in material handling needs on many Naval vessels provides the motivation to explore the modeling and control of Naval robotic and robotic assistive devices. This report addresses the design, modeling, control and analysis of position and force controlled robotic systems operating on the deck of a moving ship. First we provide background information that quantifies the motion of the ship, both in terms of frequency and amplitude. We then formulate the motion of the ship in terms of homogeneous transforms. This transformation provides a link between the motion of the ship and the base of a manipulator. We model the kinematics of a manipulator as a serial extension of the ship motion. We then show how to use these transforms to formulate the kinetic and potential energy of a general, multi-degree of freedom manipulator moving on a ship. As a demonstration, we consider two examples: a one degree-of-freedom system experiencing three sea states operating in a plane to verify the methodology and a 3 degree of freedom system experiencing all six degrees of ship motion to illustrate the ease of computation and complexity of the solution. The first series of simulations explore the impact wave motion has on tracking performance of a position controlled robot. We provide a preliminary comparison between conventional linear control and Repetitive Learning Control (RLC) and show how fixed time delay RLC breaks down due to the varying nature wave disturbance frequency. Next, we explore the impact wave motion disturbances have on Human Amplification Technology (HAT). We begin with a description of the traditional HAT control methodology. Simulations show that the motion of the base of the robot, due to ship motion, generates disturbances forces reflected to the operator that significantly degrade the positioning accuracy and resolution at higher sea states. As with position-controlled manipulators, augmenting the control with a Repetitive

FY2014 Propulsion Materials R&D Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

None

2015-05-01

The Propulsion Materials Program actively supports the energy security and reduction of greenhouse emissions goals of VTO by investigating and identifying the materials properties that are most essential for continued development of cost-effective, highly efficient, and environmentally friendly next-generation heavy and light-duty powertrains. The technical approaches available to enhance propulsion systems focus on improvements in both vehicle efficiency and fuel substitution, both of which must overcome the performance limitations of the materials currently in use. Propulsion Materials Program activities work with national laboratories, industry experts, and VTO powertrain systems (e.g., Advanced Combustion Engines [ACE], Advanced Power Electronics and Electrical Machines [APEEM], and fuels) teams to develop strategies that overcome materials limitations in future powertrain performance. The technical maturity of the portfolio of funded projects ranges from basic science to subsystem prototype validation. Projects within a Propulsion Materials Program activity address materials concerns that directly impact critical technology barriers within each of the above programs, including barriers that impact fuel efficiency, thermal management, emissions reduction, improved reliability, and reduced manufacturing costs. The program engages only the barriers that result from material property limitations and represent fundamental, high-risk materials issues.

Initial Skill Acquisition of Handrim Wheelchair Propulsion: A New Perspective.

Science.gov (United States)

Vegter, Riemer J K; de Groot, Sonja; Lamoth, Claudine J; Veeger, Dirkjan Hej; van der Woude, Lucas H V

2014-01-01

To gain insight into cyclic motor learning processes, hand rim wheelchair propulsion is a suitable cyclic task, to be learned during early rehabilitation and novel to almost every individual. To propel in an energy efficient manner, wheelchair users must learn to control bimanually applied forces onto the rims, preserving both speed and direction of locomotion. The purpose of this study was to evaluate mechanical efficiency and propulsion technique during the initial stage of motor learning. Therefore, 70 naive able-bodied men received 12-min uninstructed wheelchair practice, consisting of three 4-min blocks separated by 2 min rest. Practice was performed on a motor-driven treadmill at a fixed belt speed and constant power output relative to body mass. Energy consumption and the kinetics of propulsion technique were continuously measured. Participants significantly increased their mechanical efficiency and changed their propulsion technique from a high frequency mode with a lot of negative work to a longer-slower movement pattern with less power losses. Furthermore a multi-level model showed propulsion technique to relate to mechanical efficiency. Finally improvers and non-improvers were identified. The non-improving group was already more efficient and had a better propulsion technique in the first block of practice (i.e., the fourth minute). These findings link propulsion technique to mechanical efficiency, support the importance of a correct propulsion technique for wheelchair users and show motor learning differences.

Engine cycle design considerations for nuclear thermal propulsion systems

International Nuclear Information System (INIS)

Pelaccio, D.G.; Scheil, C.M.; Collins, J.T.

1993-01-01

A top-level study was performed which addresses nuclear thermal propulsion system engine cycle options and their applicability to support future Space Exploration Initiative manned lunar and Mars missions. Technical and development issues associated with expander, gas generator, and bleed cycle near-term, solid core nuclear thermal propulsion engines are identified and examined. In addition to performance and weight the influence of the engine cycle type on key design selection parameters such as design complexity, reliability, development time, and cost are discussed. Representative engine designs are presented and compared. Their applicability and performance impact on typical near-term lunar and Mars missions are shown

Some concepts of future nuclear ship

International Nuclear Information System (INIS)

Fujino, Masataka

2000-01-01

Characteristic features of nuclear power generation are as follows: (1) Thermal energy can be continuously extracted for a long time without fuel feed, (2) Nuclear energy is suitable for generating huge power, (3) Oxygen is unnecessary for combustion of fuel, and (4) Unlike fossil fuel, nuclear power generation does not exhaust NOx, SOx, and CO 2 : it can be considered environmentally friendly. In view of these features, the Japan Atomic Energy Research Institute commissioned the Shipbuilding Research Association of Japan (JSRA) to survey what kinds of nuclear ship would be put to practical use in the near future. For this purpose, a research committee was organized in 1992 by the JSRA, and concluded its investigation in 1996. The main aim of this research was to clarify the requirements of ship performance as nuclear ships, and then to extract the technical issues of the marine reactor installed in nuclear ships to be solved. As a result of the survey, it was suggested that displacement-type large high-speed container ship would be one of the promising future nuclear merchant ships, and 6500 m deep-sea and 600 m undersea scientific research submersibles would be other promising nuclear special purpose ships. At the same time, various requirements of marine reactors, which are expected to be installed in these ships, were clarified mainly from the technical viewpoints. (author)

Cryogenic propulsion for lunar and Mars missions

Science.gov (United States)

Redd, Larry

1988-01-01

Future missions to the moon and Mars have been investigated with regard to propulsion system selection. The results of this analysis show that near state-of-the-art LO2/LH2 propulsion technology provides a feasible means of performing lunar missions and trans-Mars injections. In other words, existing cryogenic space engines with certain modifications and product improvements would be suitable for these missions. In addition, present day cryogenic system tankage and structural weights appear to scale reasonably when sizing for large payload and high energy missions such as sending men to Mars.

Mechanical efficiency of two commercial lever-propulsion mechanisms for manual wheelchair locomotion.

Science.gov (United States)

Lui, Jordon; MacGillivray, Megan K; Sheel, A William; Jeyasurya, Jeswin; Sadeghi, Mahsa; Sawatzky, Bonita Jean

2013-01-01

The purpose of this study was to (1) evaluate the mechanical efficiency (ME) of two commercially available lever-propulsion mechanisms for wheelchairs and (2) compare the ME of lever propulsion with hand rim propulsion within the same wheelchair. Of the two mechanisms, one contained a torsion spring while the other used a roller clutch design. We hypothesized that the torsion spring mechanism would increase the ME of propulsion due to a passive recovery stroke enabled by the mechanism. Ten nondisabled male participants with no prior manual wheeling experience performed submaximal exercise tests using both lever-propulsion mechanisms and hand rim propulsion on two different wheelchairs. Cardiopulmonary parameters including oxygen uptake (VO2), heart rate (HR), and energy expenditure (En) were determined. Total external power (Pext) was measured using a drag test protocol. ME was determined by the ratio of Pext to En. Results indicated no significant effect of lever-propulsion mechanism for all physiological measures tested. This suggests that the torsion spring did not result in a physiological benefit compared with the roller clutch mechanism. However, both lever-propulsion mechanisms showed decreased VO2 and HR and increased ME (as a function of slope) compared with hand rim propulsion (p propulsion mechanisms tested are more mechanically efficient than conventional hand rim propulsion, especially when slopes are encountered.

Effect of plasma distribution on propulsion performance in electrodeless plasma thrusters

Science.gov (United States)

Takao, Yoshinori; Takase, Kazuki; Takahashi, Kazunori

2016-09-01

A helicon plasma thruster consisting of a helicon plasma source and a magnetic nozzle is one of the candidates for long-lifetime thrusters because no electrodes are employed to generate or accelerate plasma. A recent experiment, however, detected the non-negligible axial momentum lost to the lateral wall boundary, which degrades thruster performance, when the source was operated with highly ionized gases. To investigate this mechanism, we have conducted two-dimensional axisymmetric particle-in-cell (PIC) simulations with the neutral distribution obtained by Direct Simulation Monte Carlo (DSMC) method. The numerical results have indicated that the axially asymmetric profiles of the plasma density and potential are obtained when the strong decay of neutrals occurs at the source downstream. This asymmetric potential profile leads to the accelerated ion towards the lateral wall, leading to the non-negligible net axial force in the opposite direction of the thrust. Hence, to reduce this asymmetric profile by increasing the neutral density at downstream and/or by confining plasma with external magnetic field would result in improvement of the propulsion performance. These effects are also analyzed by PIC/DSMC simulations.

Thermal hydro-dynamic behavior of the nuclear-powered ship Mutsu in the power-up test

International Nuclear Information System (INIS)

Ishida, Toshihisa; Kusunoki, Tsuyoshi; Tanaka, Yoshimi; Yao, Toshiaki; Inoue, Kimio; Ochiai, Masa-aki

1991-01-01

The first Japanese nuclear ship N.S. Mutsu was tested with heavy load changes as ones of the full scale start-up tests. This paper describes the results of power increasing test, test of crash astern propulsion from ahead cruising, and turbine trip test; In the power increasing test, the main steam flow rate increased from 20 % flow to 70 % flow in 13 seconds; In the test of crash astern propulsion from ahead cruising, an astern turbine maneuvering handle was drawn to the position equivalent to about 60 % reactor power in 30 seconds after an ahead turbine stopping; In the turbine trip test, the ahead turbine was tripped manually at about 100 % power operation. From these tests it was verified that the Mutsu reactor is capable to respond smoothly and safely to the heavy load change without reactor scram, without workings of the pressurizer relief valve and main steam dump valve, and without need of any manual adjustment of the reactor control system. (author)

Brief review on pulse laser propulsion

Science.gov (United States)

Yu, Haichao; Li, Hanyang; Wang, Yan; Cui, Lugui; Liu, Shuangqiang; Yang, Jun

2018-03-01

Pulse laser propulsion (PLP) is an advanced propulsion concept can be used across a variety of fields with a wide range of applications. PLP reflects superior payload as well as decreased launch costs in comparison with other conventional methods of producing thrust, such as chemical propulsion or electric propulsion. Numerous researchers have attempted to exploit the potential applications of PLP. This paper first reviews concepts relevant to PLP, including the propulsion modes, breakdown regimes, and propulsion efficiency; the propulsion targets for different materials with the pulse laser are then discussed in detail, including the propulsion of solid and liquid microspheres. PLP applications such as the driven microsatellite, target surface particle removal, and orbital debris removal are also discussed. Although the PLP has been applied to a variety of fields, further research is yet warranted to establish its application in the aerospace field.

NASA Electric Propulsion System Studies

Science.gov (United States)

Felder, James L.

2015-01-01

An overview of NASA efforts in the area of hybrid electric and turboelectric propulsion in large transport. This overview includes a list of reasons why we are looking at transmitting some or all of the propulsive power for the aircraft electrically, a list of the different types of hybrid-turbo electric propulsion systems, and the results of 4 aircraft studies that examined different types of hybrid-turbo electric propulsion systems.

Plasma propulsion for geostationary satellites for telecommunication and interplanetary missions

International Nuclear Information System (INIS)

Dudeck, M; Doveil, F; Arcis, N; Zurbach, S

2012-01-01

The advantages of electric propulsion for the orbit maintenance of geostationary satellites for telecommunications are described. Different types of plasma sources for space propulsion are presented. Due to its large performances, one of them, named Hall effect thruster is described in detail and two recent missions in space (Stentor and Smart1) using French Hall thrusters are briefly presented.

Transnucleaire's experience in ship adaptation

International Nuclear Information System (INIS)

Brachet, Y.; Vallette-Fontaine, M.

2000-01-01

Due to the application of the new IMDG regulations for the transport of radioactive material by sea, the conditions of transport of MTR spent fuel have drastically changed five years ago. In this paper, TRANSNUCLEAIRE analyses the necessary modifications to apply to existing ships in order to comply with the IMDG/INF regulations as well as with the Japanese KAISA 520 regulation. In the MTR spent fuel transport market characterized by a competitive approach, TRANSNUCLEAIRE has carried out many transports by sea in full compliance with the regulations at a price which is as close as possible to that of other industrial goods and without the need to fully dedicate the BOUGUENAIS ship to nuclear transports. Innovative ship design solutions have been implemented and accepted by different Authorities uncluding the Advisory Committee of the Japanese MOT. Due to efficient finite element calculations, benchmarked by laboratory large scale tests, high performances crushing materials have been developed in order to absorb the energy of collision between ships. These developments have led ta propose an efficient ship design complying with all the existing worldwide nuclear regulations. (author)

Recent Electric Propulsion Development Activities for NASA Science Missions

Science.gov (United States)

Pencil, Eric J.

2009-01-01

(The primary source of electric propulsion development throughout NASA is managed by the In-Space Propulsion Technology Project at the NASA Glenn Research Center for the Science Mission Directorate. The objective of the Electric Propulsion project area is to develop near-term electric propulsion technology to enhance or enable science missions while minimizing risk and cost to the end user. Major hardware tasks include developing NASA s Evolutionary Xenon Thruster (NEXT), developing a long-life High Voltage Hall Accelerator (HIVHAC), developing an advanced feed system, and developing cross-platform components. The objective of the NEXT task is to advance next generation ion propulsion technology readiness. The baseline NEXT system consists of a high-performance, 7-kW ion thruster; a high-efficiency, 7-kW power processor unit (PPU); a highly flexible advanced xenon propellant management system (PMS); a lightweight engine gimbal; and key elements of a digital control interface unit (DCIU) including software algorithms. This design approach was selected to provide future NASA science missions with the greatest value in mission performance benefit at a low total development cost. The objective of the HIVHAC task is to advance the Hall thruster technology readiness for science mission applications. The task seeks to increase specific impulse, throttle-ability and lifetime to make Hall propulsion systems applicable to deep space science missions. The primary application focus for the resulting Hall propulsion system would be cost-capped missions, such as competitively selected, Discovery-class missions. The objective of the advanced xenon feed system task is to demonstrate novel manufacturing techniques that will significantly reduce mass, volume, and footprint size of xenon feed systems over conventional feed systems. This task has focused on the development of a flow control module, which consists of a three-channel flow system based on a piezo-electrically actuated

Is effective force application in handrim wheelchair propulsion also efficient?

Science.gov (United States)

Bregman, D J J; van Drongelen, S; Veeger, H E J

2009-01-01

Efficiency in manual wheelchair propulsion is low, as is the fraction of the propulsion force that is attributed to the moment of propulsion of the wheelchair. In this study we tested the hypothesis that a tangential propulsion force direction leads to an increase in physiological cost, due to (1) the sub-optimal use of elbow flexors and extensors, and/or (2) the necessity of preventing of glenohumeral subluxation. Five able-bodied and 11 individuals with a spinal cord injury propelled a wheelchair while kinematics and kinetics were collected. The results were used to perform inverse dynamical simulations with input of (1) the experimentally obtained propulsion force, and (2) only the tangential component of that force. In the tangential force condition the physiological cost was over 30% higher, while the tangential propulsion force was only 75% of the total experimental force. According to model estimations, the tangential force condition led to more co-contraction around the elbow, and a higher power production around the shoulder joint. The tangential propulsion force led to a significant, but small 4% increase in necessity for the model to compensate for glenohumeral subluxation, which indicates that this is not a likely cause of the decrease in efficiency. The present findings support the hypothesis that the observed force direction in wheelchair propulsion is a compromise between efficiency and the constraints imposed by the wheelchair-user system. This implies that training should not be aimed at optimization of the propulsion force, because this may be less efficient and more straining for the musculoskeletal system.

Force application during handcycling and handrim wheelchair propulsion: an initial comparison.

Science.gov (United States)

Arnet, Ursina; van Drongelen, Stefan; Veeger, D H; van der Woude L, H V

2013-12-01

The aim of the study was to evaluate the external applied forces, the effectiveness of force application and the net shoulder moments of handcycling in comparison with handrim wheelchair propulsion at different inclines. Ten able-bodied men performed standardized exercises on a treadmill at inclines of 1%, 2.5% and 4% with an instrumented handbike and wheelchair that measured three-dimensional propulsion forces. The results showed that during handcycling significantly lower mean forces were applied at inclines of 2.5% (P propulsion. The force effectiveness did not differ between the devices (P = .757); however, the effectiveness did increase with higher inclines during handcycling whereas it stayed constant over all inclines for wheelchair propulsion. The resulting peak net shoulder moments were lower for handcycling compared with wheelchair propulsion at all inclines (P < .001). These results confirm the assumption that handcycling is physically less straining.

Effect of workload setting on propulsion technique in handrim wheelchair propulsion

NARCIS (Netherlands)

van Drongelen, Stefan; Arnet, Ursina; Veeger, DirkJan (H E. J); van der Woude, Lucas H. V.

Objective: To investigate the influence of workload setting (speed at constant power, method to impose power) on the propulsion technique (i.e. force and timing characteristics) in handrim wheelchair propulsion. Method: Twelve able-bodied men participated in this study. External forces were measured

Propulsion Electric Grid Simulator (PEGS) for Future Turboelectric Distributed Propulsion Aircraft

Science.gov (United States)

Choi, Benjamin B.; Morrison, Carlos; Dever, Timothy; Brown, Gerald V.

2014-01-01

NASA Glenn Research Center, in collaboration with the aerospace industry and academia, has begun the development of technology for a future hybrid-wing body electric airplane with a turboelectric distributed propulsion (TeDP) system. It is essential to design a subscale system to emulate the TeDP power grid, which would enable rapid analysis and demonstration of the proof-of-concept of the TeDP electrical system. This paper describes how small electrical machines with their controllers can emulate all the components in a TeDP power train. The whole system model in Matlab/Simulink was first developed and tested in simulation, and the simulation results showed that system dynamic characteristics could be implemented by using the closed-loop control of the electric motor drive systems. Then we designed a subscale experimental system to emulate the entire power system from the turbine engine to the propulsive fans. Firstly, we built a system to emulate a gas turbine engine driving a generator, consisting of two permanent magnet (PM) motors with brushless motor drives, coupled by a shaft. We programmed the first motor and its drive to mimic the speed-torque characteristic of the gas turbine engine, while the second motor and drive act as a generator and produce a torque load on the first motor. Secondly, we built another system of two PM motors and drives to emulate a motor driving a propulsive fan. We programmed the first motor and drive to emulate a wound-rotor synchronous motor. The propulsive fan was emulated by implementing fan maps and flight conditions into the fourth motor and drive, which produce a torque load on the driving motor. The stator of each PM motor is designed to travel axially to change the coupling between rotor and stator. This feature allows the PM motor to more closely emulate a wound-rotor synchronous machine. These techniques can convert the plain motor system into a unique TeDP power grid emulator that enables real-time simulation performance

Prediction of applied forces in handrim wheelchair propulsion.

Science.gov (United States)

Lin, Chien-Ju; Lin, Po-Chou; Guo, Lan-Yuen; Su, Fong-Chin

2011-02-03

Researchers of wheelchair propulsion have usually suggested that a wheelchair can be properly designed using anthropometrics to reduce high mechanical load and thus reduce pain and damage to joints. A model based on physiological features and biomechanical principles can be used to determine anthropometric relationships for wheelchair fitting. To improve the understanding of man-machine interaction and the mechanism through which propulsion performance been enhanced, this study develops and validates an energy model for wheelchair propulsion. Kinematic data obtained from ten able-bodied and ten wheelchair-dependent users during level propulsion at an average velocity of 1m/s were used as the input of a planar model with the criteria of increasing efficiency and reducing joint load. Results demonstrate that for both experienced and inexperienced users, predicted handrim contact forces agree with experimental data through an extensive range of the push. Significant deviations that were mostly observed in the early stage of the push phase might result from the lack of consideration of muscle dynamics and wrist joint biomechanics. The proposed model effectively verified the handrim contact force patterns during dynamic propulsion. Users do not aim to generate mechanically most effective forces to avoid high loadings on the joints. Copyright © 2010 Elsevier Ltd. All rights reserved.

LOX/LH2 propulsion system for launch vehicle upper stage, test results

Science.gov (United States)

Ikeda, T.; Imachi, U.; Yuzawa, Y.; Kondo, Y.; Miyoshi, K.; Higashino, K.

1984-01-01

The test results of small LOX/LH2 engines for two propulsion systems, a pump fed system and a pressure fed system are reported. The pump fed system has the advantages of higher performances and higher mass fraction. The pressure fed system has the advantages of higher reliability and relative simplicity. Adoption of these cryogenic propulsion systems for upper stage of launch vehicle increases the payload capability with low cost. The 1,000 kg thrust class engine was selected for this cryogenic stage. A thrust chamber assembly for the pressure fed propulsion system was tested. It is indicated that it has good performance to meet system requirements.

Laser Propulsion - Quo Vadis

International Nuclear Information System (INIS)

Bohn, Willy L.

2008-01-01

First, an introductory overview of the different types of laser propulsion techniques will be given and illustrated by some historical examples. Second, laser devices available for basic experiments will be reviewed ranging from low power lasers sources to inertial confinement laser facilities. Subsequently, a status of work will show the impasse in which the laser propulsion community is currently engaged. Revisiting the basic relations leads to new avenues in ablative and direct laser propulsion for ground based and space based applications. Hereby, special attention will be devoted to the impact of emerging ultra-short pulse lasers on the coupling coefficient and specific impulse. In particular, laser sources and laser propulsion techniques will be tested in microgravity environment. A novel approach to debris removal will be discussed with respect to the Satellite Laser Ranging (SRL) facilities. Finally, some non technical issues will be raised aimed at the future prospects of laser propulsion in the international community

Integrated propulsion for near-Earth space missions. Volume 1: Executive summary

Science.gov (United States)

Dailey, C. L.; Meissinger, H. F.; Lovberg, R. H.; Zafran, S.

1981-01-01

Tradeoffs between electric propulsion system mass ratio and transfer time from LEO to GEO were conducted parametrically for various thruster efficiency, specific impulse, and other propulsion parameters. A computer model was developed for performing orbit transfer calculations which included the effects of aerodynamic drag, radiation degradation, and occultation. The tradeoff results showed that thruster technology areas for integrated propulsion should be directed towards improving primary thruster efficiency in the range from 1500 to 2500 seconds, and be continued towards reducing specific mass. Comparison of auxiliary propulsion systems showed large total propellant mass savings with integrated electric auxiliary propulsion. Stationkeeping is the most demanding on orbit propulsion requirement. At area densities above 0.5 sq m/kg, East-West stationkeeping requirements from solar pressure exceed North-South stationkeeping requirements from gravitational forces. A solar array pointing strategy was developed to minimize the effects of atmospheric drag at low altitude, enabling electric propulsion to initiate orbit transfer at Shuttle's maximum cargo carrying altitude. Gravity gradient torques are used during ascent to sustain the spacecraft roll motion required for optimum solar array illumination. A near optimum cover glass thickness of 6 mils was established for LEO to GEO transfer.

Advanced Propulsion System Studies for General Aviation Aircraft

Science.gov (United States)

Eisenberg, Joseph D. (Technical Monitor); German, Jon

2003-01-01

This final report addresses the following topics: Market Impact Analysis (1) assessment of general aviation, including commuter/regional, aircraft market impact due to incorporation of advanced technology propulsion system on acquisition and operating costs, job creation and/or manpower demand, and future fleet size; (2) selecting an aircraft and engine for the study by focusing on the next generation 19-passenger commuter and the Williams International FJ44 turbofan engine growth. Propulsion System Analysis Conducted mission analysis studies and engine cycle analysis to define a new commuter mission and required engine performance, define acquisition and operating costs and, select engine configuration and initiated preliminary design for hardware modifications required. Propulsion System Benefits (1) assessed and defined engine emissions improvements, (2) assessed and defined noise reduction potential and, (3) conducted a cost analysis impact study. Review of Relevant NASA Programs Conducted literature searches using NERAC and NASA RECON services for related technology in the emissions and acoustics area. Preliminary Technology Development Plans Defined plan to incorporate technology improvements for an FJ44-2 growth engine in performance, emissions, and noise suppression.

MW-Class Electric Propulsion System Designs for Mars Cargo Transport

Science.gov (United States)

Gilland, James H.; LaPointe, Michael R.; Oleson, Steven; Mercer, Carolyn; Pencil, Eric; Maosn, Lee

2011-01-01

Multi-kilowatt electric propulsion systems are well developed and have been used on commercial and military satellites in Earth orbit for several years. Ion and Hall thrusters have also propelled robotic spacecraft to encounters with asteroids, the Moon, and minor planetary bodies within the solar system. High power electric propulsion systems are currently being considered to support piloted missions to near earth asteroids, as cargo transport for sustained lunar or Mars exploration, and for very high-power piloted missions to Mars and the outer planets. Using NASA Mars Design Architecture 5.0 as a reference, a preliminary parametric analysis was performed to determine the suitability of a nuclear powered, MW-class electric propulsion system for Mars cargo transport. For this initial analysis, high power 100-kW Hall thrusters and 250-kW VASIMR engines were separately evaluated to determine optimum vehicle architecture and estimated performance. The DRA 5.0 cargo mission closed for both propulsion options, delivering a 100 t payload to Mars orbit and reducing the number of heavy lift launch vehicles from five in the baseline DRA 5.0 architecture to two using electric propulsion. Under an imposed single engine-out mission success criteria, the VASIMR system took longer to reach Mars than did the Hall system, arising from the need to operate the VASIMR thrusters in pairs during the spiral out from low Earth orbit.

STG-ET: DLR electric propulsion test facility

Directory of Open Access Journals (Sweden)

Andreas Neumann

2017-04-01

Full Text Available DLR operates the High Vacuum Plume Test Facility Göttingen – Electric Thrusters (STG-ET. This electric propulsion test facility has now accumulated several years of EP-thruster testing experience. Special features tailored to electric space propulsion testing like a large vacuum chamber mounted on a low vibration foundation, a beam dump target with low sputtering, and a performant pumping system characterize this facility. The vacuum chamber is 12.2m long and has a diameter of 5m. With respect to accurate thruster testing, the design focus is on accurate thrust measurement, plume diagnostics, and plume interaction with spacecraft components. Electric propulsion thrusters have to run for thousands of hours, and with this the facility is prepared for long-term experiments. This paper gives an overview of the facility, and shows some details of the vacuum chamber, pumping system, diagnostics, and experiences with these components.

Development of nuclear powered ship in Japan

International Nuclear Information System (INIS)

Sato, Hiroshi

1976-01-01

The development of nuclear merchant ship in Japan was started in 1955 by the establishment of Nuclear Ship Study Group, and since then, the investigation, test and research on nuclear ships have been continued. As a result, a nuclear ocean observation and supply ship was designed for trial. Researches were carried out also in JAERI and Institute for Technical Research of Ships. Meanwhile, the nuclear icebreaker Lenin was completed in Soviet Union in 1959, the nuclear ship Savannah set out for maiden voyage in U.S. in 1962, and the construction of the nuclear ore carrier Otto Hahn was prepared in FRG. Japan Nuclear Ship Development Corp. was established in 1963, and started the design and construction of the first nuclear ship in Japan, Mutsu. The basic policy in the construction is the improvement of nuclear ship technology, the securing of safety, and the use of domestic technologies as far as possible. The progress of the design, construction and test of the Mutsu is described. Owing to the problem of radiation leak, the development of nuclear ships stagnated for a while, but the nuclear plant of the Mutsu demonstrated the expected performance in the functional test, land criticality test and zero output test, and it is expected that the bud of the independent development brought up so far can bear valuable fruit. The independent development of marine nuclear reactors should be continued by selecting the way most suitable to Japan. (Kako, I.)

Development of Liquid Propulsion Systems Testbed at MSFC

Science.gov (United States)

Alexander, Reginald; Nelson, Graham

2016-01-01

As NASA, the Department of Defense and the aerospace industry in general strive to develop capabilities to explore near-Earth, Cis-lunar and deep space, the need to create more cost effective techniques of propulsion system design, manufacturing and test is imperative in the current budget constrained environment. The physics of space exploration have not changed, but the manner in which systems are developed and certified needs to change if there is going to be any hope of designing and building the high performance liquid propulsion systems necessary to deliver crew and cargo to the further reaches of space. To further the objective of developing these systems, the Marshall Space Flight Center is currently in the process of formulating a Liquid Propulsion Systems testbed, which will enable rapid integration of components to be tested and assessed for performance in integrated systems. The manifestation of this testbed is a breadboard engine configuration (BBE) with facility support for consumables and/or other components as needed. The goal of the facility is to test NASA developed elements, but can be used to test articles developed by other government agencies, industry or academia. Joint government/private partnership is likely the approach that will be required to enable efficient propulsion system development. MSFC has recently tested its own additively manufactured liquid hydrogen pump, injector, and valves in a BBE hot firing. It is rapidly building toward testing the pump and a new CH4 injector in the BBE configuration to demonstrate a 22,000 lbf, pump-fed LO2/LCH4 engine for the Mars lander or in-space transportation. The value of having this BBE testbed is that as components are developed they may be easily integrated in the testbed and tested. MSFC is striving to enhance its liquid propulsion system development capability. Rapid design, analysis, build and test will be critical to fielding the next high thrust rocket engine. With the maturity of the

Fish biorobotics: kinematics and hydrodynamics of self-propulsion.

Science.gov (United States)

Lauder, George V; Anderson, Erik J; Tangorra, James; Madden, Peter G A

2007-08-01

As a result of years of research on the comparative biomechanics and physiology of moving through water, biologists and engineers have made considerable progress in understanding how animals moving underwater use their muscles to power movement, in describing body and appendage motion during propulsion, and in conducting experimental and computational analyses of fluid movement and attendant forces. But it is clear that substantial future progress in understanding aquatic propulsion will require new lines of attack. Recent years have seen the advent of one such new avenue that promises to greatly broaden the scope of intellectual opportunity available to researchers: the use of biorobotic models. In this paper we discuss, using aquatic propulsion in fishes as our focal example, how using robotic models can lead to new insights in the study of aquatic propulsion. We use two examples: (1) pectoral fin function, and (2) hydrodynamic interactions between dorsal and caudal fins. Pectoral fin function is characterized by considerable deformation of individual fin rays, as well as spanwise (along the length) and chordwise (across the fin) deformation and area change. The pectoral fin can generate thrust on both the outstroke and instroke. A robotic model of the pectoral fin replicates this result, and demonstrates the effect of altering stroke kinematics on the pattern of force production. The soft dorsal fin of fishes sheds a distinct vortex wake that dramatically alters incoming flow to the tail: the dorsal fin and caudal fin act as dual flapping foils in series. This design can be replicated with a dual-foil flapping robotic device that demonstrates this phenomenon and allows examination of regions of the flapping performance space not available to fishes. We show how the robotic flapping foil device can also be used to better understand the significance of flexible propulsive surfaces for locomotor performance. Finally we emphasize the utility of self

Ergonomical valorization of working spaces in multipurpose ships.

Science.gov (United States)

Seif, Mehdi; Degiuli, Nastija; Muftić, Osman

2003-06-01

In this work it is shown how anthropological data are among the most needed factors in ergonomical valorization of crew working spaces. Ship's working or living environment involves many unique human factors, which should be specially considered in our case as limitation of crew space. In this work we have chosen ships of different years of construction to prove this tendency. As a micro study, the work posture analysis using the pulling force experiment is performed in order to determine lumbar moment, intra-abdominal pressure as a measure of evaluating and comparing different crew work positions. As a macro-study, the "crew work posture analysis" was carried out by the use of the data collected from real cases. The most probable work postures in different spaces of a ship are classified and after some corrections of the work place the profile and its grade were determined. The "statistical analysis for real ship's spaces" is also performed, as well as another macro study, in order to show some real designed ship spaces from the point of view of the allocated volume.

Status and Mission Applicability of NASA's In-Space Propulsion Technology Project

Science.gov (United States)

Anderson, David J.; Munk, Michelle M.; Dankanich, John; Pencil, Eric; Liou, Larry

2009-01-01

The In-Space Propulsion Technology (ISPT) project develops propulsion technologies that will enable or enhance NASA robotic science missions. Since 2001, the ISPT project developed and delivered products to assist technology infusion and quantify mission applicability and benefits through mission analysis and tools. These in-space propulsion technologies are applicable, and potentially enabling for flagship destinations currently under evaluation, as well as having broad applicability to future Discovery and New Frontiers mission solicitations. This paper provides status of the technology development, near-term mission benefits, applicability, and availability of in-space propulsion technologies in the areas of advanced chemical thrusters, electric propulsion, aerocapture, and systems analysis tools. The current chemical propulsion investment is on the high-temperature Advanced Material Bipropellant Rocket (AMBR) engine providing higher performance for lower cost. Investments in electric propulsion technologies focused on completing NASA's Evolutionary Xenon Thruster (NEXT) ion propulsion system, a 0.6-7 kW throttle-able gridded ion system, and the High Voltage Hall Accelerator (HiVHAC) thruster, which is a mid-term product specifically designed for a low-cost electric propulsion option. Aerocapture investments developed a family of thermal protections system materials and structures; guidance, navigation, and control models of blunt-body rigid aeroshells; atmospheric models for Earth, Titan, Mars and Venus; and models for aerothermal effects. In 2009 ISPT started the development of propulsion technologies that would enable future sample return missions. The paper describes the ISPT project's future focus on propulsion for sample return missions. The future technology development areas for ISPT is: Planetary Ascent Vehicles (PAV), with a Mars Ascent Vehicle (MAV) being the initial development focus; multi-mission technologies for Earth Entry Vehicles (MMEEV) needed

Electric vehicle propulsion alternatives

Science.gov (United States)

Secunde, R. R.; Schuh, R. M.; Beach, R. F.

1983-01-01

Propulsion technology development for electric vehicles is summarized. Analytical studies, technology evaluation, and the development of technology for motors, controllers, transmissions, and complete propulsion systems are included.

Fuel Effective Photonic Propulsion

Science.gov (United States)

Rajalakshmi, N.; Srivarshini, S.

2017-09-01

With the entry of miniaturization in electronics and ultra-small light-weight materials, energy efficient propulsion techniques for space travel can soon be possible. We need to go for such high speeds so that the generation’s time long interstellar missions can be done in incredibly short time. Also renewable energy like sunlight, nuclear energy can be used for propulsion instead of fuel. These propulsion techniques are being worked on currently. The recently proposed photon propulsion concepts are reviewed, that utilize momentum of photons generated by sunlight or onboard photon generators, such as blackbody radiation or lasers, powered by nuclear or solar power. With the understanding of nuclear photonic propulsion, in this paper, a rough estimate of nuclear fuel required to achieve the escape velocity of Earth is done. An overview of the IKAROS space mission for interplanetary travel by JAXA, that was successful in demonstrating that photonic propulsion works and also generated additional solar power on board, is provided; which can be used as a case study. An extension of this idea for interstellar travel, termed as ‘Star Shot’, aims to send a nanocraft to an exoplanet in the nearest star system, which could be potentially habitable. A brief overview of the idea is presented.

High-temperature turbopump assembly for space nuclear thermal propulsion

Science.gov (United States)

Overholt, David M.

1993-01-01

The development of a practical, high-performance nuclear rocket by the U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program places high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio. The operating parameters arising from these goals drive the propellant-pump design. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is effected by rapid heating of the propellant from 100 K to thousands of degrees in the particle-bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. One approach to achieve high performance is to use an uncooled carbon-carbon nozzle and duct turbine inlet. The high-temperature capability is obtained by using carbon-carbon throughout the TPA hot section. Carbon-carbon components in development include structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines plus a wide variety of other turbomachinery applications.

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion

Science.gov (United States)

Overholt, David M.

1993-06-01

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications.

High-temperature turbopump assembly for space nuclear thermal propulsion

International Nuclear Information System (INIS)

Overholt, D.M.

1993-01-01

The development of a practical, high-performance nuclear rocket by the U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program places high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio. The operating parameters arising from these goals drive the propellant-pump design. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is effected by rapid heating of the propellant from 100 K to thousands of degrees in the particle-bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. One approach to achieve high performance is to use an uncooled carbon-carbon nozzle and duct turbine inlet. The high-temperature capability is obtained by using carbon-carbon throughout the TPA hot section. Carbon-carbon components in development include structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines plus a wide variety of other turbomachinery applications

Carbon-carbon turbopump concept for Space Nuclear Thermal Propulsion

International Nuclear Information System (INIS)

Overholt, D.M.

1993-06-01

The U.S. Air Force Space Nuclear Thermal Propulsion (SNTP) program is placing high priority on maximizing specific impulse (ISP) and thrust-to-weight ratio in the development of a practical high-performance nuclear rocket. The turbopump design is driven by these goals. The liquid hydrogen propellant is pressurized and pumped to the reactor inlet by the turbopump assembly (TPA). Rocket propulsion is from rapid heating of the propellant from 180 R to thousands of degrees in the particle bed reactor (PBR). The exhausted propellant is then expanded through a high-temperature nozzle. A high-performance approach is to use an uncooled carbon-carbon nozzle and duct turbine inlet. Carbon-carbon components are used throughout the TPA hot section to obtain the high-temperature capability. Several carbon-carbon components are in development including structural parts, turbine nozzles/stators, and turbine rotors. The technology spinoff is applicable to conventional liquid propulsion engines and many other turbomachinery applications. 3 refs

Shipping

OpenAIRE

Wijnolst, N.; Wergeland, T.

1996-01-01

Shipping is a multi-faceted industry which is rather complex to define from an academic point of view. This book attempts to grasp these complexities and provide the reader with an overview of the main topics and terminology in shipping. The book is based on material from our courses in shipping at the universities in Delft and Bergen. As with our lectures, we draw upon quite a va ried material, from research studies at a high academic level to lower level student work and purely descriptive ...

In-Space Propulsion Technology Program Solar Electric Propulsion Technologies

Science.gov (United States)

Dankanich, John W.

2006-01-01

NASA's In-space Propulsion (ISP) Technology Project is developing new propulsion technologies that can enable or enhance near and mid-term NASA science missions. The Solar Electric Propulsion (SEP) technology area has been investing in NASA s Evolutionary Xenon Thruster (NEXT), the High Voltage Hall Accelerator (HiVHAC), lightweight reliable feed systems, wear testing, and thruster modeling. These investments are specifically targeted to increase planetary science payload capability, expand the envelope of planetary science destinations, and significantly reduce the travel times, risk, and cost of NASA planetary science missions. Status and expected capabilities of the SEP technologies are reviewed in this presentation. The SEP technology area supports numerous mission studies and architecture analyses to determine which investments will give the greatest benefit to science missions. Both the NEXT and HiVHAC thrusters have modified their nominal throttle tables to better utilize diminished solar array power on outbound missions. A new life extension mechanism has been implemented on HiVHAC to increase the throughput capability on low-power systems to meet the needs of cost-capped missions. Lower complexity, more reliable feed system components common to all electric propulsion (EP) systems are being developed. ISP has also leveraged commercial investments to further validate new ion and hall thruster technologies and to potentially lower EP mission costs.

Advanced electrostatic ion thruster for space propulsion

Science.gov (United States)

Masek, T. D.; Macpherson, D.; Gelon, W.; Kami, S.; Poeschel, R. L.; Ward, J. W.

1978-01-01

The suitability of the baseline 30 cm thruster for future space missions was examined. Preliminary design concepts for several advanced thrusters were developed to assess the potential practical difficulties of a new design. Useful methodologies were produced for assessing both planetary and earth orbit missions. Payload performance as a function of propulsion system technology level and cost sensitivity to propulsion system technology level are among the topics assessed. A 50 cm diameter thruster designed to operate with a beam voltage of about 2400 V is suggested to satisfy most of the requirements of future space missions.

A development approach for nuclear thermal propulsion

International Nuclear Information System (INIS)

Buden, D.

1992-01-01

The cost and time to develop nuclear thermal propulsion systems are very approach dependent. The objectives addressed are the development of an ''acceptable'' nuclear thermal propulsion system that can be used as part of the transportation system for people to explore Mars and the enhancement performance of other missions, within highly constrained budgets and schedules. To accomplish this, it was necessary to identify the cost drivers considering mission parameters, safety of the crew, mission success, facility availability and time and cost to construct new facilities, qualification criteria, status of technologies, management structure, and use of such system engineering techniques as concurrent engineering

Evolutionary use of nuclear electric propulsion

International Nuclear Information System (INIS)

Hack, K.J.; George, J.A.; Riehl, J.P.; Gilland, J.H.

1990-01-01

Evolving new propulsion technologies through a rational and conscious effort to minimize development costs and program risks while maximizing the performance benefits is intuitively practical. A phased approach to the evolution of nuclear electric propulsion from use on planetary probes, to lunar cargo vehicles, and finally to manned Mars missions with a concomitant growth in technology is considered. Technology levels and system component makeup are discussed for nuclear power systems and both ion and magnetoplasmadynamic thrusters. Mission scenarios are described, which include analysis of a probe to Pluto, a lunar cargo mission, Martian split, all-up, and quick-trip mission options. Evolutionary progression of the use of NEP in such missions is discussed. 26 refs

The TRANSRAPID propulsion system - development and test results

Energy Technology Data Exchange (ETDEWEB)

Henning, U [Siemens AG, Erlangen (Germany); Kamp, P G [Siemens AG, Erlangen (Germany); Hochleitner, J [Siemens AG, Erlangen (Germany)

1996-12-31

The structure of the propulsion system for the Transrapid comprises a number of components which are located along the guideway. These drive components are temporarily switched together to form the drive control zones necessary to permit maglev operation over the guideway. The paper describes the development of the stationary propulsion converter with GTO thyristors. The drive components are tested under realistic operating conditions. The test results confirm the performance capability as well as verify the suitability of the concept for use in revenue service. (HW)

Cooling of Electric Motors Used for Propulsion on SCEPTOR

Science.gov (United States)

Christie, Robert J.; Dubois, Arthur; Derlaga, Joseph M.

2017-01-01

NASA is developing a suite of hybrid-electric propulsion technologies for aircraft. These technologies have the benefit of lower emissions, diminished noise, increased efficiency, and reduced fuel burn. These will provide lower operating costs for aircraft operators. Replacing internal combustion engines with distributed electric propulsion is a keystone of this technology suite, but presents many new problems to aircraft system designers. One of the problems is how to cool these electric motors without adding significant aerodynamic drag, cooling system weight or fan power. This paper discusses the options evaluated for cooling the motors on SCEPTOR (Scalable Convergent Electric Propulsion Technology and Operations Research): a project that will demonstrate Distributed Electric Propulsion technology in flight. Options for external and internal cooling, inlet and exhaust locations, ducting and adjustable cowling, and axial and centrifugal fans were evaluated. The final design was based on a trade between effectiveness, simplicity, robustness, mass and performance over a range of ground and flight operation environments.

Designing Adaptable Ships: Modularity and Flexibility in Future Ship Designs

Science.gov (United States)

2016-01-01

with motors, belts, shafts , seals, valves, hose spindles , and switches. If ship installation is not installed, the system will be status quo. Ship...Impact: the current centrifugal purifiers (Alfa-Laval) have experienced frequent failures with motor, belts, shafts , seals, valves, hose spindles ... Designing Adaptable Ships Modularity and Flexibility in Future Ship Designs John F. Schank, Scott Savitz, Ken Munson, Brian Perkinson, James

Concept Study of Radio Frequency (RF Plasma Thruster for Space Propulsion

Directory of Open Access Journals (Sweden)

Anna-Maria Theodora ANDREESCU

2016-12-01

Full Text Available Electric thrusters are capable of accelerating ions to speeds that are impossible to reach using chemical reaction. Recent advances in plasma-based concepts have led to the identification of electromagnetic (RF generation and acceleration systems as able to provide not only continuous thrust, but also highly controllable and wide-range exhaust velocities. For Future Space Propulsion there is a pressing need for low pressure, high mass flow rate and controlled ion energies. This paper explores the potential of using RF heated plasmas for space propulsion in order to mitigate the electric propulsion problems caused by erosion and gain flexibility in plasma manipulation. The main key components of RF thruster architecture are: a feeding system able to provide the required neutral gas flow, plasma source chamber, antenna/electrodes wrapped around the discharge tube and optimized electromagnetic field coils for plasma confinement. A preliminary analysis of system performance (thrust, specific impulse, efficiency is performed along with future plans of Space Propulsion based on this new concept of plasma mechanism.

Ion Beam Propulsion Study

Science.gov (United States)

2008-01-01

The Ion Beam Propulsion Study was a joint high-level study between the Applied Physics Laboratory operated by NASA and ASRC Aerospace at Kennedy Space Center, Florida, and Berkeley Scientific, Berkeley, California. The results were promising and suggested that work should continue if future funding becomes available. The application of ion thrusters for spacecraft propulsion is limited to quite modest ion sources with similarly modest ion beam parameters because of the mass penalty associated with the ion source and its power supply system. Also, the ion source technology has not been able to provide very high-power ion beams. Small ion beam propulsion systems were used with considerable success. Ion propulsion systems brought into practice use an onboard ion source to form an energetic ion beam, typically Xe+ ions, as the propellant. Such systems were used for steering and correction of telecommunication satellites and as the main thruster for the Deep Space 1 demonstration mission. In recent years, "giant" ion sources were developed for the controlled-fusion research effort worldwide, with beam parameters many orders of magnitude greater than the tiny ones of conventional space thruster application. The advent of such huge ion beam sources and the need for advanced propulsion systems for exploration of the solar system suggest a fresh look at ion beam propulsion, now with the giant fusion sources in mind.

Advanced Earth-to-orbit propulsion technology information, dissemination and research

Science.gov (United States)

Wu, S. T.

1995-01-01

In this period of performance a conference (The 1994 Conference on Advanced Earth-to-Orbit Propulsion Technology) was organized and implemented by the University of Alabama in Huntsville and held May 15-17 to assemble and disseminate the current information on Advanced Earth-to-Orbit Propulsion Technology. The results were assembled for publication as NASA-CP-3282, Volume 1 and 2 and NASA-CP-3287.

INFLUENCE OF OPERABILITY CRITERIA LIMITING VALUES ON SHIP SPEED

Directory of Open Access Journals (Sweden)

Jasna Prpić-Oršić

2016-09-01

Full Text Available When the ship is caught in heavy seas, there are two manoeuvres that the shipmaster can undertake to avoid excessive ship motion and hull damage: changing course or voluntary speed reduction. This paper presents a study of the effect of the various voluntary speed reduction criteria to attainable speed of ship on seaway. The speed loss is calculated by taking into account wind and wave effect on ship speed, the engine and propeller performance in actual seas as well as the mass inertia of the ship. The attainable ship speed for ship in head, following and beam waves by accounting for voluntary speed reduction is estimated for various significant wave height. The criteria of slamming, deck wetness, propeller emergence, excessive accelerations and roll are taken into account. The impact of variations of the limiting values of certain criteria due to which the captain intentionally reduces the ship speed is analysed and discussed.

Hull-Propeller Interaction and Its Effect on Propeller Cavitation

DEFF Research Database (Denmark)

Regener, Pelle Bo

In order to predict the required propulsion power for a ship reliably and accurately, it is not sufficient to only evaluate the resistance of the hull and the propeller performance in open water alone. Interaction effects between hull and propeller can even be a decisive factor in ship powering...... prediction and design optimization. The hull-propeller interaction coefficients of effective wake fraction, thrust deduction factor, and relative rotative efficiency are traditionally determined by model tests. Self-propulsion model tests consistently show an increase in effective wake fractions when using...... velocities. This offers an opportunity for additional insight into hull-propeller interaction and the propeller’s actual operating condition behind the ship, as the actual (effective) inflow is computed. Self-propulsion simulations at model and full scale were carried out for a bulk carrier, once...

Ship Domain Model for Multi-ship Collision Avoidance Decision-making with COLREGs Based on Artificial Potential Field

Directory of Open Access Journals (Sweden)

TengFei Wang

2017-03-01

Full Text Available A multi-ship collision avoidance decision-making and path planning formulation is studied in a distributed way. This paper proposes a complete set of solutions for multi-ship collision avoidance in intelligent navigation, by using a top-to-bottom organization to structure the system. The system is designed with two layers: the collision avoidance decision-making and the path planning. Under the general requirements of the International Regulations for Preventing Collisions at Sea (COLREGs, the performance of distributed path planning decision-making for anti-collision is analyzed for both give-way and stand-on ships situations, including the emergency actions taken by the stand-on ship in case of the give-way ship’s fault of collision avoidance measures. The Artificial Potential Field method(APF is used for the path planning in details. The developed APF method combined with the model of ship domain takes the target ships’ speed and course in-to account, so that it can judge the moving characteristics of obstacles more accurately. Simulation results indicate that the system proposed can work effectiveness.

Propulsion requirements for reusable single-stage-to-orbit rocket vehicles

Science.gov (United States)

Stanley, Douglas O.; Engelund, Walter C.; Lepsch, Roger

1994-05-01

The conceptual design of a single-stage-to-orbit (SSTO) vehicle using a wide variety of evolutionary technologies has recently been completed as a part of NASA's Advanced Manned Launch System (AMLS) study. The employment of new propulsion system technologies is critical to the design of a reasonably sized, operationally efficient SSTO vehicle. This paper presents the propulsion system requirements identified for this near-term AMLS SSTO vehicle. Sensitivities of the vehicle to changes in specific impulse and sea-level thrust-to-weight ratio are examined. The results of a variety of vehicle/propulsion system trades performed on the near-term AMLS SSTO vehicle are also presented.

Exercise training programs to improve hand rim wheelchair propulsion capacity: a systematic review.

NARCIS (Netherlands)

Zwinkels, M.; Verschuren, O.; Janssen, T.W.J.; Ketelaar, M.; Takken, T.

2014-01-01

Objective: An adequate wheelchair propulsion capacity is required to perform daily life activities. Exercise training may be effective to gain or improve wheelchair propulsion capacity. This review investigates whether different types of exercise training programs are effective in improving

Exercise training programs to improve hand rim wheelchair propulsion capacity: a systematic review

NARCIS (Netherlands)

Zwinkels, M.G.J.; Verschuren, O.W.; Janssen, T.; Ketelaar, M.; Takken, T.; Backx, F.J.G.; Groot, J.F. de; Smits, D.W.; Volman, MJM

2014-01-01

Objective: An adequate wheelchair propulsion capacity is required to perform daily life activities. Exercise training may be effective to gain or improve wheelchair propulsion capacity. This review investigates whether different types of exercise training programs are effective in improving

Adaptive Beamforming Algorithms for Tow Ship Noise Canceling

NARCIS (Netherlands)

Robert, M.K.; Beerens, S.P.

2002-01-01

In towed array sonar, the directional noise originating from the tow ship, mainly machinery and hydrodynamic noise, often limits the sonar performance. When processed with classical beamforming techniques, loud tow ship noise induces high sidelobes that may hide detection of quiet targets in forward

Designing Indonesian Liner Shipping Network

Directory of Open Access Journals (Sweden)

Armand Omar Moeis

2017-06-01

Full Text Available As the largest archipelago nation in the world, Indonesia’s logistics system has not shown excellence according to the parameters of logistics performance index and based on logistics costs percentages from overall GDP. This is due to the imbalances of trading on the western and eastern regions in Indonesia, which impacts the transportation systems costs to and from the eastern regions. Therefore, it is imperative to improve the competitiveness of Indonesian maritime logistics through maritime logistics network design. This research will focus on three levels of decision making in logistics network design, which include type of ships in the strategic level, shipping routes in the tactical level, and container allocation in the operational level with implementing butterfly routes in Indonesia’s logistics networking problems. Furthermore, this research will analyze the impact of Pendulum Nusantara and Sea Toll routes against the company profits and percentages of containers shipped. This research will also foresee how demand uncertainties and multi-period planning should affect decision making in designing the Indonesian Liner Shipping Network.

Alternative propulsion for automobiles

CERN Document Server

Stan, Cornel

2017-01-01

The book presents – based on the most recent research and development results worldwide - the perspectives of new propulsion concepts such as electric cars with batteries and fuel cells, and furthermore plug in hybrids with conventional and alternative fuels. The propulsion concepts are evaluated based on specific power, torque characteristic, acceleration behaviour, specific fuel consumption and pollutant emissions. The alternative fuels are discussed in terms of availability, production, technical complexity of the storage on board, costs, safety and infrastructure. The book presents summarized data about vehicles with electric and hybrid propulsion. The propulsion of future cars will be marked by diversity – from compact electric city cars and range extender vehicles for suburban and rural areas up to hybrid or plug in SUV´s, Pick up´s and luxury class automobiles.

Hybrid Propulsion Systems for Remotely Piloted Aircraft Systems

Directory of Open Access Journals (Sweden)

Mithun Abdul Sathar Eqbal

2018-03-01

Full Text Available The development of more efficient propulsion systems for aerospace vehicles is essential to achieve key objectives. These objectives are to increase efficiency while reducing the amount of carbon-based emissions. Hybrid electric propulsion (HEP is an ideal means to maintain the energy density of hydrocarbon-based fuels and utilize energy-efficient electric machines. A system that integrates different propulsion systems into a single system, with one being electric, is termed an HEP system. HEP systems have been studied previously and introduced into Land, Water, and Aerial Vehicles. This work presents research into the use of HEP systems in Remotely Piloted Aircraft Systems (RPAS. The systems discussed in this paper are Internal Combustion Engine (ICE–Electric Hybrid systems, ICE–Photovoltaic (PV Hybrid systems, and Fuel-Cell Hybrid systems. The improved performance characteristics in terms of fuel consumption and endurance are discussed.

Intelligent Propulsion System Foundation Technology: Summary of Research

Science.gov (United States)

2008-01-01

The purpose of this cooperative agreement was to develop a foundation of intelligent propulsion technologies for NASA and industry that will have an impact on safety, noise, emissions, and cost. These intelligent engine technologies included sensors, electronics, communications, control logic, actuators, smart materials and structures, and system studies. Furthermore, this cooperative agreement helped prepare future graduates to develop the revolutionary intelligent propulsion technologies that will be needed to ensure pre-eminence of the U.S. aerospace industry. This Propulsion 21 - Phase 11 program consisted of four primary research areas and associated work elements at Ohio universities: 1.0 Turbine Engine Prognostics, 2.0 Active Controls for Emissions and Noise Reduction, 3.0 Active Structural Controls and Performance, and 4.0 System Studies and Integration. Phase l, which was conducted during the period August 1, 2003, through September 30, 2004, has been reported separately.

Variable geometry gas turbines for improving the part-load performance of marine combined cycles - Combined cycle performance

DEFF Research Database (Denmark)

Haglind, Fredrik

2011-01-01

The part-load performance of combined cycles intended for naval use is of great importance, and it is influenced by the gas turbine configuration and load control strategy. This paper is aimed at quantifying the effects of variable geometry gas turbines on the part-load efficiency for combined...... cycles used for ship propulsion. Moreover, the paper is aimed at developing methodologies and deriving models for part-load simulations suitable for energy system analysis of various components within combined cycle power plants. Two different gas turbine configurations are studied, a two-shaft aero......-derivative configuration and a single-shaft industrial configuration. The results suggest that by the use of variable geometry gas turbines, the combined cycle part-load performance can be improved. In order to minimise the voyage fuel consumption, a combined cycle featuring two-shaft gas turbines with VAN control...

Response to severe changes of load on the reactor system of nuclear ship Mutsu

International Nuclear Information System (INIS)

Ishida, Toshihisa; Kusunoki, Tsuyoshi; Ochiai, Masa-aki; Tanaka, Yoshimi; Yao, Toshiaki; Inoue, Kimio.

1993-01-01

The response of the nuclear power system of N.S. Mutsu to severe changes of load have been studied from records taken during the power-raising tests performed on the ship in 1990. The records examined were those involving the most severe load changes foreseen for marine reactors: (a) sharp load increase with total steam flow raised from 25 to 70 % rated full flow in 13s, (b) crash astern maneuver with the position of propulsion turbine command handle changed-taking several seconds-from cruising ahead to STOP, and after about 50s, further changed-taking 30s-to bring the astern propulsion turbine to full speed-to consume approximately 60 % rated total steam flow and (c) turbine trip with the ahead turbine intentionally tripped when operating at roughly 100 % rated total steam flow. The foregoing records from load changes-of severity beyond what is foreseen for land-based reactors-proved that the Mutsu reactor is capable of responding smoothly and securely to such severe load changes. These load changes occasioned relatively large mismatches between reactor power supply and steam flow demand, but with notable freedom from any conspicuous overshooting or hunting of the reactor power. This performance can be attributed to (a) correct functioning of the automatic power control system, (b) effective contribution of the self-regulating reactor control property deriving from the large negative feedback between moderator temperature and reactivity, and (c) the ample inventories of coolant in the primary and secondary loops. The responses to load change are discussed covering those relevant to (a) reactor power, (b) primary loop pressure, and (c) steam generator pressure, with particular reference to the differences seen in response to mild and to severe load changes. (author)

Space transportation propulsion USSR launcher technology, 1990

Science.gov (United States)

1991-01-01

Space transportation propulsion U.S.S.R. launcher technology is discussed. The following subject areas are covered: Energia background (launch vehicle summary, Soviet launcher family) and Energia propulsion characteristics (booster propulsion, core propulsion, and growth capability).

Nuclear Bi-Brayton system for aircraft propulsion

International Nuclear Information System (INIS)

Pierce, B.L.

1979-01-01

Recent studies have shown the desirability of new system concept for nuclear aircraft propulsion utilizing the Bi-Brayton system concept, permits coupling of a gas cooled reactor to the power transmission and conversion system in a manner such as to fulfill the safety criteria while eliminating the need for a high temperature intermediate heat exchanger or shaft penetrations of the containment vessel. This system has been shown to minimize the component development required and to allow reduction in total propulsion system weight. This paper presents a description of the system concept and the results of the definition and evaluation studies to date. Parametric and reference system definition studies have been performed. The closed-cycle Bi-Brayton system and component configurations and weight estimates have been derived. Parametric evaluation and cycle variation studies have been performed and interpreted. 7 refs

Reactors for nuclear electric propulsion

Energy Technology Data Exchange (ETDEWEB)

Buden, D.; Angelo, J.A. Jr.

1981-01-01

Propulsion is the key to space exploitation and power is the key to propulsion. This paper examines the role of nuclear fission reactors as the primary power source for high specific impulse electric propulsion systems for space missions of the 1980s and 1990s. Particular mission applications include transfer to and a reusable orbital transfer vehicle from low-Earth orbit to geosynchronous orbit, outer planet exploration and reconnaissance missions, and as a versatile space tug supporting lunar resource development. Nuclear electric propulsion is examined as an indispensable component in space activities of the next two decades.

Reactors for nuclear electric propulsion

International Nuclear Information System (INIS)

Buden, D.; Angelo, J.A. Jr.

1981-01-01

Propulsion is the key to space exploitation and power is the key to propulsion. This paper examines the role of nuclear fission reactors as the primary power source for high specific impulse electric propulsion systems for space missions of the 1980s and 1990s. Particular mission applications include transfer to and a reusable orbital transfer vehicle from low-Earth orbit to geosynchronous orbit, outer planet exploration and reconnaissance missions, and as a versatile space tug supporting lunar resource development. Nuclear electric propulsion is examined as an indispensable component in space activities of the next two decades

Electric rail gun application to space propulsion

International Nuclear Information System (INIS)

Barber, J.P.

1979-01-01

The paper examines the possibility of using the DC electric gun principles as a space vehicle propulsion system, capable of producing intermediate thrust levels. The application of an electromagnetic launch technique, called the DC electric rail gun, to the space propulsion concept of O'Neill, is examined. It is determined that the DC electric rail gun offers very high projectile accelerations and a very significant potential for reducing the size and mass of a reaction motor for space application. A detailed description of rail gun principles is given and some simple expressions for the accelerating force, gun impedance, power supply requirements, and system performance are discussed

Optimization of ship inner shell to improve the safety of seagoing transport ship

Directory of Open Access Journals (Sweden)

Yan-Yun YU

2013-09-01

Full Text Available A practical Ship Inner Shell Optimization Method (SISOM, the purpose of which is to improve the safety of the seagoing transport ship by decreasing the maximum Still Water Bending Moment (SWBM of the hull girder under all typical loading conditions, is presented in this paper. The objective of SISOM is to make the maximum SWBM minimum, and the section areas of the inner shell are taken as optimization variables. The main requirements of the ship performances, such as cargo hold capacity, propeller and rudder immersion, bridge visibility, damage stability and prevention of pollution etc., are taken as constraints. The penalty function method is used in SISOM to change the above nonlinear constraint problem into an unconstrained one, which is then solved by applying the steepest descent method. After optimization, the optimal section area distribution of the inner shell is obtained, and the shape of inner shell is adjusted according to the optimal section area. SISOM is applied to a product oil tanker and a bulk carrier, and the maximum SWBM of the two ships is significantly decreased by changing the shape of inner shell plate slightly. The two examples prove that SISOM is highly efficient and valuable to engineering practice.

Fish's Muscles Distortion and Pectoral Fins Propulsion of Lift-Based Mode

Science.gov (United States)

Yang, S. B.; Han, X. Y.; Qiu, J.

As a sort of MPF(median and/or paired fin propulsion), pectoral fins propulsion makes fish easier to maneuver than other propulsion, according to the well-established classification scheme proposed by Webb in 1984. Pectoral fins propulsion is classified into oscillatory propulsion, undulatory propulsion and compound propulsion. Pectoral fins oscillatory propulsion, is further ascribable to two modes: drag-based mode and lift-based mode. And fish exhibits strong cruise ability by using lift-based mode. Therefore to robot fish design using pectoral fins lift-based mode will bring a new revolution to resources exploration in blue sea. On the basis of the wave plate theory, a kinematic model of fish’s pectoral fins lift-based mode is established associated with the behaviors of cownose ray (Rhinoptera bonasus) in the present work. In view of the power of fish’s locomotion from muscle distortion, it would be helpful benefit to reveal the mechanism of fish’s locomotion variation dependent on muscles distortion. So this study puts forward the pattern of muscles distortion of pectoral fins according to the character of skeletons and muscles of cownose ray in morphology and simulates the kinematics of lift-based mode using nonlinear analysis software. In the symmetrical fluid field, the model is simulated left-right symmetrically or asymmetrically. The results qualitatively show how muscles distortion determines the performance of fish locomotion. Finally the efficient muscles distortion associated with the preliminary dynamics is induced.

Overview: Solar Electric Propulsion Concept Designs for SEP Technology Demonstration Mission

Science.gov (United States)

Mcguire, Melissa L.; Hack, Kurt J.; Manzella, David; Herman, Daniel

2014-01-01

JPC presentation of the Concept designs for NASA Solar Electric Propulsion Technology Demonstration mission paper. Multiple Solar Electric Propulsion Technology Demonstration Missions were developed to assess vehicle performance and estimated mission cost. Concepts ranged from a 10,000 kg spacecraft capable of delivering 4000 kg of payload to one of the Earth Moon Lagrange points in support of future human-crewed outposts to a 180 kg spacecraft capable of performing an asteroid rendezvous mission after launched to a geostationary transfer orbit as a secondary payload.

THE FUTURE OF SPACECRAFT NUCLEAR PROPULSION

OpenAIRE

Jansen, Frank

2014-01-01

This paper summarizes the advantages of space nuclear power and propulsion systems. It describes the actual status of international power level dependent spacecraft nuclear propulsion missions, especially the high power EU-Russian MEGAHIT study including the Russian Megawatt-Class Nuclear Power Propulsion System, the NASA GRC project and the low and medium power EU DiPoP study. Space nuclear propulsion based mission scenarios of these studies are sketched as well.

Classification of Ship Routing and Scheduling Problems in Liner Shipping

DEFF Research Database (Denmark)

Kjeldsen, Karina Hjortshøj

2011-01-01

This article provides a classification scheme for ship routing and scheduling problems in liner shipping in line with the current and future operational conditions of the liner shipping industry. Based on the classification, the literature is divided into groups whose main characteristics...

Additive Manufacturing of Aerospace Propulsion Components

Science.gov (United States)

Misra, Ajay K.; Grady, Joseph E.; Carter, Robert

2015-01-01

The presentation will provide an overview of ongoing activities on additive manufacturing of aerospace propulsion components, which included rocket propulsion and gas turbine engines. Future opportunities on additive manufacturing of hybrid electric propulsion components will be discussed.

Ship Roll Damping Control

DEFF Research Database (Denmark)

Perez, Tristan; Blanke, Mogens

2012-01-01

limitations and large variations of the spectral characteristics of wave-induced roll motion. This tutorial paper presents an account of the development of various ship roll motion control systems together with the challenges associated with their design. It discusses the assessment of performance...

Near Real Time Ship Detection Experiments

Science.gov (United States)

Brusch, S.; Lehner, S.; Schwarz, E.; Fritz, T.

2010-04-01

A new Near Real Time (NRT) ship detection processor SAINT (SAR AIS Integrated Toolbox) was developed in the framework of the ESA project MARISS. Data are received at DLRs ground segment DLR-BN (Neustrelitz, Germany). Results of the ship detection are available on ftp server within 30 min after the acquisition started. The detectability of ships on Synthetic Aperture Radar (SAR) ERS-2, ENVISAT ASAR and TerraSAR-X (TS-X) images is validated by coastal (live) AIS and space AIS. The monitoring areas chosen for surveillance are the North-, Baltic Sea, and Cape Town. The detectability in respect to environmental parameters like wind field, sea state, currents and changing coastlines due to tidal effects is investigated. In the South Atlantic a tracking experiment of the German research vessel Polarstern has been performed. Issues of piracy in particular in respect to ships hijacked at the Somali coast are discussed. Some examples using high resolution images from TerraSAR-X are given.

Advanced Chemical Propulsion System Study

Science.gov (United States)

Portz, Ron; Alexander, Leslie; Chapman, Jack; England, Chris; Henderson, Scott; Krismer, David; Lu, Frank; Wilson, Kim; Miller, Scott

2007-01-01

A detailed; mission-level systems study has been performed to show the benefit resulting from engine performance gains that will result from NASA's In-Space Propulsion ROSS Cycle 3A NRA, Advanced Chemical Technology sub-topic. The technology development roadmap to accomplish the NRA goals are also detailed in this paper. NASA-Marshall and NASA-JPL have conducted mission-level studies to define engine requirements, operating conditions, and interfaces. Five reference missions have been chosen for this analysis based on scientific interest, current launch vehicle capability and trends in space craft size: a) GTO to GEO, 4800 kg, delta-V for GEO insertion only approx.1830 m/s; b) Titan Orbiter with aerocapture, 6620 kg, total delta V approx.210 m/s, mostly for periapsis raise after aerocapture; c) Enceladus Orbiter (Titan aerocapture) 6620 kg, delta V approx.2400 m/s; d) Europa Orbiter, 2170 kg, total delta V approx.2600 m/s; and e) Mars Orbiter, 2250 kg, total delta V approx.1860 m/s. The figures of merit used to define the benefit of increased propulsion efficiency at the spacecraft level include propulsion subsystem wet mass, volume and overall cost. The objective of the NRA is to increase the specific impulse of pressure-fed earth storable bipropellant rocket engines to greater than 330 seconds with nitrogen tetroxide and monomothylhydrazine propellants and greater than 335 , seconds with nitrogen tetroxide and hydrazine. Achievement of the NRA goals will significantly benefit NASA interplanetary missions and other government and commercial opportunities by enabling reduced launch weight and/or increased payload. The study also constitutes a crucial stepping stone to future development, such as pump-fed storable engines.

Energetic Combustion Devices for Aerospace Propulsion and Power

Science.gov (United States)

Litchford, Ron J.

2000-01-01

Chemical reactions have long been the mainstay thermal energy source for aerospace propulsion and power. Although it is widely recognized that the intrinsic energy density limitations of chemical bonds place severe constraints on maximum realizable performance, it will likely be several years before systems based on high energy density nuclear fuels can be placed into routine service. In the mean time, efforts to develop high energy density chemicals and advanced combustion devices which can utilize such energetic fuels may yield worthwhile returns in overall system performance and cost. Current efforts in this vein are being carried out at NASA MSFC under the direction of the author in the areas of pulse detonation engine technology development and light metals combustion devices. Pulse detonation engines are touted as a low cost alternative to gas turbine engines and to conventional rocket engines, but actual performance and cost benefits have yet to be convincingly demonstrated. Light metal fueled engines also offer potential benefits in certain niche applications such as aluminum/CO2 fueled engines for endo-atmospheric Martian propulsion. Light metal fueled MHD generators also present promising opportunities with respect to electric power generation for electromagnetic launch assist. This presentation will discuss the applications potential of these concepts with respect to aero ace propulsion and power and will review the current status of the development efforts.

Software To Secure Distributed Propulsion Simulations

Science.gov (United States)

Blaser, Tammy M.

2003-01-01

Distributed-object computing systems are presented with many security threats, including network eavesdropping, message tampering, and communications middleware masquerading. NASA Glenn Research Center, and its industry partners, has taken an active role in mitigating the security threats associated with developing and operating their proprietary aerospace propulsion simulations. In particular, they are developing a collaborative Common Object Request Broker Architecture (CORBA) Security (CORBASec) test bed to secure their distributed aerospace propulsion simulations. Glenn has been working with its aerospace propulsion industry partners to deploy the Numerical Propulsion System Simulation (NPSS) object-based technology. NPSS is a program focused on reducing the cost and time in developing aerospace propulsion engines

Supersonic propulsion technology. [variable cycle engines

Science.gov (United States)

Powers, A. G.; Coltrin, R. E.; Stitt, L. E.; Weber, R. J.; Whitlow, J. B., Jr.

1979-01-01

Propulsion concepts for commercial supersonic transports are discussed. It is concluded that variable cycle engines, together with advanced supersonic inlets and low noise coannular nozzles, provide good operating performance for both supersonic and subsonic flight. In addition, they are reasonably quiet during takeoff and landing and have acceptable exhaust emissions.

Steady State Thermal Analyses of SCEPTOR X-57 Wingtip Propulsion

Science.gov (United States)

Schnulo, Sydney L.; Chin, Jeffrey C.; Smith, Andrew D.; Dubois, Arthur

2017-01-01

Electric aircraft concepts enable advanced propulsion airframe integration approaches that promise increased efficiency as well as reduced emissions and noise. NASA's fully electric Maxwell X-57, developed under the SCEPTOR program, features distributed propulsion across a high aspect ratio wing. There are 14 propulsors in all: 12 high lift motor that are only active during take off and climb, and 2 larger motors positioned on the wingtips that operate over the entire mission. The power electronics involved in the wingtip propulsion are temperature sensitive and therefore require thermal management. This work focuses on the high and low fidelity heat transfer analysis methods performed to ensure that the wingtip motor inverters do not reach their temperature limits. It also explores different geometry configurations involved in the X-57 development and any thermal concerns. All analyses presented are performed at steady state under stressful operating conditions, therefore predicting temperatures which are considered the worst-case scenario to remain conservative.

An approach to high speed ship ride quality simulation

Science.gov (United States)

Malone, W. L.; Vickery, J. M.

1975-01-01

The high speeds attained by certain advanced surface ships result in a spectrum of motion which is higher in frequency than that of conventional ships. This fact along with the inclusion of advanced ride control features in the design of these ships resulted in an increased awareness of the need for ride criteria. Such criteria can be developed using data from actual ship operations in varied sea states or from clinical laboratory experiments. A third approach is to simulate ship conditions using measured or calculated ship motion data. Recent simulations have used data derived from a math model of Surface Effect Ship (SES) motion. The model in turn is based on equations of motion which have been refined with data from scale models and SES of up to 101 600-kg (100-ton) displacement. Employment of broad band motion emphasizes the use of the simulators as a design tool to evaluate a given ship configuration in several operational situations and also serves to provide data as to the overall effect of a given motion on crew performance and physiological status.

The Potential for Ambient Plasma Wave Propulsion

Science.gov (United States)

Gilland, James H.; Williams, George J.

2016-01-01

A truly robust space exploration program will need to make use of in-situ resources as much as possible to make the endeavor affordable. Most space propulsion concepts are saddled with one fundamental burden; the propellant needed to produce momentum. The most advanced propulsion systems currently in use utilize electric and/or magnetic fields to accelerate ionized propellant. However, significant planetary exploration missions in the coming decades, such as the now canceled Jupiter Icy Moons Orbiter, are restricted by propellant mass and propulsion system lifetimes, using even the most optimistic projections of performance. These electric propulsion vehicles are inherently limited in flexibility at their final destination, due to propulsion system wear, propellant requirements, and the relatively low acceleration of the vehicle. A few concepts are able to utilize the environment around them to produce thrust: Solar or magnetic sails and, with certain restrictions, electrodynamic tethers. These concepts focus primarily on using the solar wind or ambient magnetic fields to generate thrust. Technically immature, quasi-propellantless alternatives lack either the sensitivity or the power to provide significant maneuvering. An additional resource to be considered is the ambient plasma and magnetic fields in solar and planetary magnetospheres. These environments, such as those around the Sun or Jupiter, have been shown to host a variety of plasma waves. Plasma wave propulsion takes advantage of an observed astrophysical and terrestrial phenomenon: Alfven waves. These are waves that propagate in the plasma and magnetic fields around and between planets and stars. The generation of Alfven waves in ambient magnetic and plasma fields to generate thrust is proposed as a truly propellantless propulsion system which may enable an entirely new matrix of exploration missions. Alfven waves are well known, transverse electromagnetic waves that propagate in magnetized plasmas at

Integrating SHM and Time Variant System Performance of Naval Ship Structures For Near Real Time Decision Making Under Uncertainty: A Comprehensive Framework

Science.gov (United States)

2016-12-06

performance of damaged ships. Reducing risk associated with loss of ship due to a post-accident collapse or disintegration of the hull during tow or rescue...In order to allow small regions of the hull extremities to plastify, it is assumed that the plasticized area is located within the extreme plates and...the damage is based on the percentage of plasticized area within the considered hull section. Therefore, the damage ratios associated with each

Development of a model for the prediction of the fuel consumption and nitrogen oxides emission trade-off for large ships

DEFF Research Database (Denmark)

Larsen, Ulrik; Pierobon, Leonardo; Baldi, Francesco

2015-01-01

The international regulations on fuel efficiency and NOx emissions of commercial ships motivate the investigation of new system layouts, which can comply with the regulations. In combustion engines, measures to reduce the fuel consumption often lead to increased NOx emissions and careful consider...... that increased system complexity can lead to lower fuel consumption and NOx. Fuel consumption reductions of up to 9% with a 6.5% NOx reduction were achieved using a hybrid turbocharger and organic Rankine cycle waste heat recovery system.......The international regulations on fuel efficiency and NOx emissions of commercial ships motivate the investigation of new system layouts, which can comply with the regulations. In combustion engines, measures to reduce the fuel consumption often lead to increased NOx emissions and careful...... consideration of this trade-off mechanism is required in the design of marine propulsion systems. This study investigates five different configurations of two-stroke diesel-based machinery systems for large ships and their influence on the mentioned trade-off. Numerical models of a low-speed two-stroke diesel...

Overview of NASA Iodine Hall Thruster Propulsion System Development

Science.gov (United States)

Smith, Timothy D.; Kamhawi, Hani; Hickman, Tyler; Haag, Thomas; Dankanich, John; Polzin, Kurt; Byrne, Lawrence; Szabo, James

2016-01-01

NASA is continuing to invest in advancing Hall thruster technologies for implementation in commercial and government missions. The most recent focus has been on increasing the power level for large-scale exploration applications. However, there has also been a similar push to examine applications of electric propulsion for small spacecraft in the range of 300 kg or less. There have been several recent iodine Hall propulsion system development activities performed by the team of the NASA Glenn Research Center, the NASA Marshall Space Flight Center, and Busek Co. Inc. In particular, the work focused on qualification of the Busek 200-W BHT-200-I and development of the 600-W BHT-600-I systems. This paper discusses the current status of iodine Hall propulsion system developments along with supporting technology development efforts.

Estimation of waves and ship responses using onboard measurements

DEFF Research Database (Denmark)

Montazeri, Najmeh

This thesis focuses on estimation of waves and ship responses using ship-board measurements. This is useful for development of operational safety and performance efficiency in connection with the broader concept of onboard decision support systems. Estimation of sea state is studied using a set...... of measured ship responses, a parametric description of directional wave spectra (a generalised JONSWAP model) and the transfer functions of the ship responses. The difference between the spectral moments of the measured ship responses and the corresponding theoretically calculated moments formulates a cost...... information. The model is tested on simulated data based on known unimodal and bimodal wave scenarios. The wave parameters in the output are then compared with the true wave parameters. In addition to the numerical experiments, two sets of full-scale measurements from container ships are analysed. Herein...

Cold Gas Micro Propulsion

NARCIS (Netherlands)

Louwerse, M.C.

2009-01-01

This thesis describes the development of a micro propulsion system. The trend of miniaturization of satellites requires small sized propulsion systems. For particular missions it is important to maintain an accurate distance between multiple satellites. Satellites drift apart due to differences in

Guide to Flow Measurement for Electric Propulsion Systems

Science.gov (United States)

Frieman, Jason D.; Walker, Mitchell L. R.; Snyder, Steve

2013-01-01

In electric propulsion (EP) systems, accurate measurement of the propellant mass flow rate of gas or liquid to the thruster and external cathode is a key input in the calculation of thruster efficiency and specific impulse. Although such measurements are often achieved with commercial mass flow controllers and meters integrated into propellant feed systems, the variability in potential propellant options and flow requirements amongst the spectrum of EP power regimes and devices complicates meter selection, integration, and operation. At the direction of the Committee on Standards for Electric Propulsion Testing, a guide was jointly developed by members of the electric propulsion community to establish a unified document that contains the working principles, methods of implementation and analysis, and calibration techniques and recommendations on the use of mass flow meters in laboratory and spacecraft electric propulsion systems. The guide is applicable to EP devices of all types and power levels ranging from microthrusters to high-power ion engines and Hall effect thrusters. The establishment of a community standard on mass flow metering will help ensure the selection of the proper meter for each application. It will also improve the quality of system performance estimates by providing comprehensive information on the physical phenomena and systematic errors that must be accounted for during the analysis of flow measurement data. This paper will outline the standard methods and recommended practices described in the guide titled "Flow Measurement for Electric Propulsion Systems."

Propulsion Utilizing Laser-Driven Ponderomotive Fields for Deep-Space Missions

International Nuclear Information System (INIS)

Williams, George J.; Gilland, James H.

2009-01-01

The generation of large amplitude electric fields in plasmas by high-power lasers has been studied for several years in the context of high-energy particle acceleration. Fields on the order of GeV/m are generated in the plasma wake of the laser by non-linear ponderomotive forces. The laser fields generate longitudinal and translational electron plasma waves with phase velocities close to the speed of light. These fields and velocities offer the potential to revolutionize spacecraft propulsion, leading to extended deep space robotic probes. Based on these initial calculations, plasma acceleration by means of laser-induced ponderomotive forces appears to offer significant potential for spacecraft propulsion. Relatively high-efficiencies appear possible with proper beam conditioning, resulting in an order of magnitude more thrust than alternative concepts for high I SP (>10 5 s) and elimination of the primary life-limiting erosion phenomena associated with conventional electric propulsion systems. Ponderomotive propulsion readily lends itself to beamed power which might overcome some of the constraints of power-limited propulsion concepts. A preliminary assessment of the impact of these propulsion systems for several promising configurations on mission architectures has been conducted. Emphasizing interstellar and interstellar-precursor applications, performance and technical requirements are identified for a number of missions. The use of in-situ plasma and gas for propellant is evaluated as well.

Ship Roll Motion Control

DEFF Research Database (Denmark)

Perez, Tristan; Blanke, Mogens

2010-01-01

. This tutorial paper presents an account of the development of various ship roll motion control systems and the challenges associated with their design. The paper discusses how to assess performance, the applicability of dierent models, and control methods that have been applied in the past....

Patterns of shoulder muscle coordination vary between wheelchair propulsion techniques.

Science.gov (United States)

Qi, Liping; Wakeling, James; Grange, Simon; Ferguson-Pell, Martin

2014-05-01

This study investigated changes in the coordination patterns of shoulder muscles and wheelchair kinetics with different propulsion techniques by comparing wheelchair users' self-selected propulsion patterns with a semicircular pattern adopted after instruction. Wheelchair kinetics data were recorded by Smart(Wheel) on an ergometer, while EMG activity of seven muscles was recorded with surface electrodes on 15 able-bodied inexperienced participants. The performance data in two sessions, first using a self-selected and then the learned semicircular pattern, were compared with a paired t-test. Muscle coordination patterns across seven muscles were analyzed by principal component analysis. The semicircular pattern was characterized by significantly lower push frequency, significantly longer push length, push duration and push distance (p propulsion technique, synergistic muscles were recruited in distinct phases and displayed a clearer separation between activities in the push phase and recovery phase muscles. An instruction session in semicircular propulsion technique is recommended for the initial use of a wheelchair after an injury.

Lunar Robotic Precursor Missions Using Electric Propulsion

OpenAIRE

Winski, Richard G.

2006-01-01

A trade study is carried out for the design of electric propulsion based lunar robotic precursor missions. The focus is to understand the relationships between payload mass delivered, electric propulsion power, and trip time. The results are compared against a baseline system using chemical propulsion with LOX/H2. The major differences between the chemical propulsion based and electric propulsion based systems are presented in terms of the payload mass and trip time. It is shown that solar e...

Definition of propulsion system for V/STOL research and technology aircraft

Science.gov (United States)

1977-01-01

Wind tunnel test support, aircraft contractor support, a propulsion system computer card deck, preliminary design studies, and propulsion system development plan are reported. The Propulsion system consists of two lift/cruise turbofan engines, one turboshaft engine and one lift fan connected together with shafting into a combiner gearbox. Distortion parameter levels from 40 x 80 test data were within the established XT701-AD-700 limits. The three engine-three fan system card deck calculates either vertical or conventional flight performance, installed or uninstalled. Design study results for XT701 engine modifications, bevel gear cross shaft location, fixed and tilt fan frames and propulsion system controls are described. Optional water-alcohol injection increased total net thrust 10.3% on a 90 F day. Engines have sufficient turbine life for 500 hours of the RTA duty cycle.

Electromagnetic Emission from Electric Propulsions under Ground Conditions

Science.gov (United States)

Baranov, S. V.; Vazhenin, N. A.; Plokhikh, A. P.; Popov, G. A.

2017-12-01

Analysis and methodological generalization of available methods used for determining characteristics of intrinsic emission from electric propulsions (EP) in a radio-frequency range that can be the interference for the "Earth-spacecraft (SC)" channel of the space communication system are the subjects of this paper. Intrinsic emission from the electric propulsion in a radio-frequency range is examined in detail by the example of a measuring complex developed in RIAME MAI and the measurement results are presented. The electric field intensity distribution in a radio-frequency range for the vertical and horizontal polarizations of the received emission is considered as the main characteristics. Measurements performed for the EP intrinsic emission by using the developed complex and measurements performed in metal vacuum chambers are compared and comparative results are presented in the paper.

A Review of Laser Ablation Propulsion

International Nuclear Information System (INIS)

Phipps, Claude; Bohn, Willy; Lippert, Thomas; Sasoh, Akihiro; Schall, Wolfgang; Sinko, John

2010-01-01

Laser Ablation Propulsion is a broad field with a wide range of applications. We review the 30-year history of laser ablation propulsion from the transition from earlier pure photon propulsion concepts of Oberth and Saenger through Kantrowitz's original laser ablation propulsion idea to the development of air-breathing 'Lightcraft' and advanced spacecraft propulsion engines. The polymers POM and GAP have played an important role in experiments and liquid ablation fuels show great promise. Some applications use a laser system which is distant from the propelled object, for example, on another spacecraft, the Earth or a planet. Others use a laser that is part of the spacecraft propulsion system on the spacecraft. Propulsion is produced when an intense laser beam strikes a condensed matter surface and produces a vapor or plasma jet. The advantages of this idea are that exhaust velocity of the propulsion engine covers a broader range than is available from chemistry, that it can be varied to meet the instantaneous demands of the particular mission, and that practical realizations give lower mass and greater simplicity for a payload delivery system. We review the underlying theory, buttressed by extensive experimental data. The primary problem in laser space propulsion theory has been the absence of a way to predict thrust and specific impulse over the transition from the vapor to the plasma regimes. We briefly discuss a method for combining two new vapor regime treatments with plasma regime theory, giving a smooth transition from one regime to the other. We conclude with a section on future directions.

Risk Analysis on Ship Wreck and Container Cargo to Ship Navigation

Directory of Open Access Journals (Sweden)

Muhammad Badrus Zaman

2017-03-01

Full Text Available Wreck of a ship is an incident that must be avoided. Ship accidents are generally caused by a several cases, such as human error, natural disaster, technical errors, missed communication, poor condition of the ship, and many more. Ship wreckage have huge impact for ship navigation, environment, economics, and others. Those impact have many disadvantages for the shipowners, and also for environment. For examples the fuel spills that pollute the environment, make disturbance to sailing ship because the track for those navigation is blocked by the ship wreck and their cargo especially on shallow location (<50 m. These research will discuss the effect the container when it is floats on the sea and its interference other ships. The main objective of this study is to present a risk assessment on the environmental impact of the wreck and container cargo. Wrecks on the seabed is likely to pose a risk to passing ships. container and its contents as well as the possibility of refloat, and also their environmental risks emanating from the wreck and container cargo, such as fuels, lubricants, and chemical cargo. Variations scenario is a collision between ships that pass by floating containers. The frequency of refloating container, and the consequences of the passing ship depends on several factors, which will be the subject of research. However, because of the frequency of refloating containers is unlikely, then the risk is low and does not pose a danger to navigation. These risk assessment using risk matrix 5x5 which is the combined value of the frequency and consequences of the incident. The results of this study indicate the level of risk, whether the risk is accepted, not accepted or received by considering the costs and benefits (ALARP. To consequence, there are two parameters which energy is absorbed and the penetration occurs. The absorbed energy is divided into two, namely the energy absorbed by ship and the energy absorbed by containers. In this

Buckling of Ship Structures

CERN Document Server

Shama, Mohamed

2013-01-01

Buckling of Ship Structures presents a comprehensive analysis of the buckling problem of ship structural members. A full analysis of the various types of loadings and stresses imposed on ship plating and primary and secondary structural members is given. The main causes and consequences of the buckling mode of failure of ship structure and the methods commonly used to control buckling failure are clarified. This book contains the main equations required to determine the critical buckling stresses for both ship plating and the primary and secondary stiffening structural members. The critical buckling stresses are given for ship plating subjected to the induced various types of loadings and having the most common boundary conditions encountered in ship structures.  The text bridges the gap existing in most books covering the subject of buckling of ship structures in the classical analytical format, by putting the emphasis on the practical methods required to ensure safety against buckling of ship structur...

A Novel AHRS Inertial Sensor-Based Algorithm for Wheelchair Propulsion Performance Analysis

Directory of Open Access Journals (Sweden)

Jonathan Bruce Shepherd

2016-08-01

Full Text Available With the increasing rise of professionalism in sport, athletes, teams, and coaches are looking to technology to monitor performance in both games and training in order to find a competitive advantage. The use of inertial sensors has been proposed as a cost effective and adaptable measurement device for monitoring wheelchair kinematics; however, the outcomes are dependent on the reliability of the processing algorithms. Though there are a variety of algorithms that have been proposed to monitor wheelchair propulsion in court sports, they all have limitations. Through experimental testing, we have shown the Attitude and Heading Reference System (AHRS-based algorithm to be a suitable and reliable candidate algorithm for estimating velocity, distance, and approximating trajectory. The proposed algorithm is computationally inexpensive, agnostic of wheel camber, not sensitive to sensor placement, and can be embedded for real-time implementations. The research is conducted under Griffith University Ethics (GU Ref No: 2016/294.

Accuracy of visual wave observation from merchant ships and estimated wave loads; Accuracy of visual wave observation from merchant ships and estimated wave loads

Energy Technology Data Exchange (ETDEWEB)

Kawabe, H. [National Defense Academy, Kanagawa (Japan); Masaoka, K. [University of Osaka Prefecture, Osaka (Japan). Faculty of Engineering

1998-06-01

There is a large number of studies on discussions concerning accuracy of visual observation of waves and the correction method thereon. This paper give considerations on observation accuracy placing a viewpoint on that by merchant ships. Based on ship meteorological observation tables reported to the Meteorological Agency of Japan on meteorology in North Pacific during 14 years from 1976 to1989, wave observation values taken by merchant ships and observation ships were compared statistically to investigate the accuracy of visual wave observations carried out by merchant ships. With regard to wave heights, the observation values taken by the observation ships and the merchant ships have strong correlation, where the merchant ships evaluate them somewhat higher than the observation ships. Regarding wave cycles of wind waves, the merchant ships tend to have the observation values on longer cycle side. Correlation between the observations values by the merchant ships and the observation ships is weak both in wind waves and swells. There is not much of variation in accuracy of observations during daytime and at night performed by the merchant ships. It will be necessary in the future to give considerations on a method to correct the observation values on wave cycles taken by the merchant ship, and on a correction method in which both of the wave cycles and the wave heights are corrected simultaneously to make the observation values of the merchant ship equal to those of the observation ships. Thus, the observation values reported by general merchant ships in a large number every year will have to be utilized more effectively. 11 refs., 21 figs., 2 tabs.

Viking FellowSHIP: Norwegian hydrogen ship on the right course

International Nuclear Information System (INIS)

Larssen-Aas, Kari

2006-01-01

In the future fuel cells will change the world of shipping's economical conditions, and environmental effects from this industry. A new model of a hydrogen fuelled ship was presented at the ONS exhibition in Stavanger 2006. The technology may revolutionize the shipping industry. A brief description of the project is presented (ml)

Estimation of real ship propelling performance by the surface velocity lattice method using model ship flow field data; Mokeisen ryujo data wo mochiita hyomen uzu koshiho ni yoru jissen suishin seino no suitei

Energy Technology Data Exchange (ETDEWEB)

Kai, H; Ikehata, M; Sakai, S [Yokohama National University, Yokohama (Japan). Faculty of Engineering

1997-10-01

This is basically a technique wherein the wing element method is replaced by a surface vortex lattice method. A horseshoe vortex of unknown intensity and source surface of known intensity are distributed on the wing surface and, under conditions that the fluid will not cross the boundary, the intensity of horseshoe vortex circulation is calculated for the solution of the fluid field. For the simulation of a real ship in navigation, the required propeller revolution thrust is determined using the real ship resistance value and real ship thrust reduction factor estimated from a model ship resistance test by extrapolation. The calculation of propeller performance is conducted in the quasi-steady condition using the force of fluid working on one wing for each wing angle (with the wing rotated at the increment of 6 degrees), and the thrust and torque are determined using the averages of values obtained in one cycle. It is found that the torque value is overestimated in a considerable degree in the wing element theory. In the surface vortex lattice method, both thrust and torque values agree with experimental values mostly, and this method is found to be accurate enough as a navigation element calculation tool when many panels are considered. 4 refs., 5 figs., 1 tab.

Experimental approach of plasma supersonic expansion physics and of Hall effect propulsion systems

International Nuclear Information System (INIS)

Mazouffre, Stephane

2009-01-01

This report for accreditation to supervise research (HDR) proposes a synthesis of scientific and research works performed by the author during about ten years. Thus, a first part addresses studies on plasma rarefied supersonic flows: expansion through a sonic hole and through a Laval nozzle. The next part addresses the study of plasma propulsion for spacecraft, and more particularly electric propulsion based on the Hall effect: phenomena of ionic and atomic transport, characteristics of the electric field, energy deposition on walls, basic scale laws, related works, hybrid Hall-RF propulsion systems. The third part presents perspectives and projects related to propulsion by Hall effect (research topics, planned researches, a European project on high power, hybrid Hall-RF propulsion) and to ions-ions plasma (the PEGASES concept, the NExET test installation, RF source of negative ions and magnetic trap)