1,544,510 research outputs found

    Overview of Advanced Stirling and Gas Turbine Engine Development Programs and Implications for Solar Thermal Electrical Applications

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    The DOE automotive advanced engine development projects managed by the NASA Lewis Research Center were described. These included one Stirling cycle engine development and two air Brayton cycle development. Other engine research activities included: (1) an air Brayton engine development sponsored by the Gas Research Institute, and (2) plans for development of a Stirling cycle engine for space use. Current and potential use of these various engines with solar parabolic dishes were discussed

    Cross Validation Of Neural Network Applications For Automatic New Topic Identification

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    There are recent studies in the literature on automatic topic-shift identification in Web search engine user sessions; however most of this work applied their topic-shift identification algorithms on data logs from a single search engine. The purpose of this study is to provide the cross-validation of an artificial neural network application to automatically identify topic changes in a web search engine user session by using data logs of different search engines for training and testing the neural network. Sample data logs from the Norwegian search engine FAST (currently owned by Overture) and Excite are used in this study. Findings of this study suggest that it could be possible to identify topic shifts and continuations successfully on a particular search engine user session using neural networks that are trained on a different search engine data log

    Jay Carter Enterprises, Incorporated steam engine

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    The Small Community Solar Thermal Power Experiment (SCSE) selected an organic rankine cycle (ORC) engine driving a high speed permanent magnet alternator (PMA) as the baseline power conversion subsystem (PCS) design. The back-up conceptual PCS design is a steam engine driving an induction alternator delivering power directly to the grid. The development of the automotive reciprocating simple rankine cycle steam engine and how an engine of similar design might be incorporated into the SCSE is discussed. A description of the third generation automotive engine is included along with some preliminary test data. Tests were conducted with the third generation engine driving an induction alternator delivering power directly to the grid. The purpose of these tests is to further verify the effects of expander inlet temperature, input thermal power level, expansion ratio, and other parameters affecting engine performance to aid in the development of an SCSE PCS

    Meta-heuristic algorithms in car engine design: a literature survey

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    Meta-heuristic algorithms are often inspired by natural phenomena, including the evolution of species in Darwinian natural selection theory, ant behaviors in biology, flock behaviors of some birds, and annealing in metallurgy. Due to their great potential in solving difficult optimization problems, meta-heuristic algorithms have found their way into automobile engine design. There are different optimization problems arising in different areas of car engine management including calibration, control system, fault diagnosis, and modeling. In this paper we review the state-of-the-art applications of different meta-heuristic algorithms in engine management systems. The review covers a wide range of research, including the application of meta-heuristic algorithms in engine calibration, optimizing engine control systems, engine fault diagnosis, and optimizing different parts of engines and modeling. The meta-heuristic algorithms reviewed in this paper include evolutionary algorithms, evolution strategy, evolutionary programming, genetic programming, differential evolution, estimation of distribution algorithm, ant colony optimization, particle swarm optimization, memetic algorithms, and artificial immune system

    Recursive least squares for online dynamic identification on gas turbine engines

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    Online identification for a gas turbine engine is vital for health monitoring and control decisions because the engine electronic control system uses the identified model to analyze the performance for optimization of fuel consumption, a response to the pilot command, as well as engine life protection. Since a gas turbine engine is a complex system and operating at variant working conditions, it behaves nonlinearly through different power transition levels and at different operating points. An adaptive approach is required to capture the dynamics of its performance

    A new internal combustion engine configuration: opposed pistons with crank offset

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    [Abstract]: Theoretical and experimental performance results for a new internal combustion engine configuration are presented in this paper. The engine is a piston ported, spark ignition petrol engine which consists of two opposed pistons in a single cylinder controlled by two synchronously timed crankshafts at opposite ends of the cylinder. It makes use of crank offset to create the required piston motion aimed at engine efficiency improvements through thermodynamic performance gains. In particular, the engine employs full expansion in which the power stroke displaces a larger volume than the compression stroke, thereby allowing the expanding gas to reach near atmospheric pressure before the exhaust port opens. This allows more work to be done by each thermodynamic cycle. It also features a greater rate of volume change after combustion than a convention 4-stroke engine for the same crank speed. This reduces the time that the temperature difference between the gas and the cylinder is high relative to a conventional engine which in turn, should reduce the heat lost from the combustion products. Thermodynamic and friction modelling of the engine indicated that efficiencies around 38% might be achieved. However, experiments with a prototype engine demonstrated that friction losses in the engine exceeded that predicted in the original modelling

    Main Engine Selection Optimization Analysis of the Ship Caraka Jaya III Based on Engineering and Economy Cosiderations

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    Caraka Jaya III, as sister ships, built in Indonesia in the era 1990, devided into three building phases. Each phase had the different main engine. Especially for the second phase used the MAN B&W 5S26MC as main engine. After several years later, some of the engines were going to have the problems, especially for the pistons and its rings. The selected engine was not the only one that should be used. In accordance with selection the engine, the optimization procrdure offer best solution as compromise. Selecting the main engine is a complicated and time consuming task. The application of Analytic Hierarchy Process (AHP), one of the Multi Criteria Decision Making (MCDM), would promise a powerful tool for main engine selection as well as usual engineering design process. To select the candidate of the main engine it needs more criteria to obtain satisfactory solution. The criteria therefore are developed as pair wise coparison matrix leading to the mathematic solution. Analysis procedure is devided into three levels, namely, (1) criteria, (2) sub-criteria and (3) alternative of the selected engine. A consistency ratio needed as the acceptance criteria to check the solution of the pair wise comparison matrix. The final result obtained from multiplication of all matrixs on analysis, namely, SKL Diesel 8VD29/24AL- 0.149; MaK 9M20 – 0.190; Wartsila 9L20 – 0.088; Wartsila 6SW28 – 0.121; NIIGATA 8PA5L – 0.098; MAN B&W 5S26MC-0.354. According to the result, optimation solution will be MAN B&W 5S26MC or MaK 9M2

    Subatmospheric Brayton-cycle Engine Program Review

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    A solar energy powered electrical generator utilizing a Subatmospheric Brayton cycle engine is examined. The generator consists of a subatmospheric, Brayton-cycle engine and a permanent magnet (PM) alternator. The electrical power is generated by an alternator driven directly by the Brayton-cycle engine rotating group. Features that enhance reliability and performance include air foil bearings on both the Brayton-cycle engine rotating group and the PM alternator, an atmospheric-pressure solar receiver and gas-fired trim heater, and a high temperature recuperator. The subatmospheric Brayton-cycle engine design is based on that of the gas fired heat pump engine

    Rocket engine analog simulation

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    Mathematical equations simulate the operation of a rocket engine, simulate destructive and nondestructive tests to verify engine design feasibility, and investigate nonlinear variations in engine performance

    Start up system for hydrogen generator used with an internal combustion engine

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    A hydrogen generator provides hydrogen rich product gases which are mixed with the fuel being supplied to an internal combustion engine for the purpose of enabling a very lean mixture of that fuel to be used, whereby nitrous oxides emitted by the engine are minimized. The hydrogen generator contains a catalyst which must be heated to a pre-determined temperature before it can react properly. To simplify the process of heating up the catalyst at start-up time, either some of the energy produced by the engine such as engine exhaust gas, or electrical energy produced by the engine, or the engine exhaust gas may be used to heat up air which is then used to heat the catalyst
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