• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2323-2328
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• 2011

There have been many changes in Subway train types since SeoulMetro opened the Line No.1 in 1974. Propulsion control device has changed many times following the generations of control method from resistance control method which uses large resistor for the traction motor control to chopping control which uses power semiconductors and finally to inverter control. Railroad vehicle propulsion control device refers to devices such as converter/inverter which supply power for subway operation, power conversion equipment like small switching-mode power supply and traction motor. In this paper, we will analyze every part of railroad vehicle propulsion control device of SeoulMetro so we can find problems in the subway operation. And we will present propulsion control device model which makes minimized failures, efficient maintenance possible when replacing railroad vehicle later. By doing this, we hope to ensure stability and improve energy efficiency to the top.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.10
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• pp.1528-1534
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• 2015

This paper designed the railway vehicle running device with a proto-type for the railway vehicle maintenance training and developed a propulsion control device simulator equipped the imitation steering wheel. In addition, this paper applied a multi-thread technology in order to implement the staged fault and the propulsion control device protected operation test and an implementation of the failure that occur in actual rail vehicle and confirm the validity as the propulsion control device simulator for the maintenance training.

• International Journal of Internet, Broadcasting and Communication
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• v.7 no.2
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• pp.113-116
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• 2015

Generally, in the railway vehicle the driving force of gravity happens by the high-speed running and the repetitive impulse cause the degradation and the malfunction phenomenon shows differently because the durability of each component changes according to the internal and external causes. The maintenance of propulsion control device which is played the very important role as to the stable service of the railway vehicle is greatly important among them. Therefore maintenance training propulsion control device simulator is needed to maximize learning through repetition and improve the maintenance practical skills training. This paper designed the railway vehicle running device with a miniature for the railway vehicle maintenance training and developed a propulsion control device simulator equipped the imitation steering wheel.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.3-6
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• 2007

In this study, we described the Pyrovalve used in the propulsion system. It is very important to ensure its reliablity of operation because Pyrovalve is a pyrotechnic device for controlling fuel and air line of propulsion system. so we focused on improving operational reliability through several analyses and tests.

• International Journal of Aeronautical and Space Sciences
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• v.8 no.2
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• pp.121-125
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• 2007

In late 1960's, engineers of the engine manufacturer experienced that the distortion of inlet flow of turbofan and turbojet engine could cause the surge in compressor and affect overall engine operational performance, which result in the deterioration of stability of the engine. In this study, block type of inlet distortion simulating device has been developed in order to investigate the effect of inlet distortion on the deterioration of overall engine operational performance. The inlet distortion simulating device was installed in front of engine inlet in order to simulate distortion of inlet flow. The degree of inlet distortion was measured by rakes installed upstream the inlet distortion simulating device and between the engine inlet and inlet distortion simulating device. Before applying the inlet distortion simulating device to real engine, preliminary tests were performed with a simulated engine in order to verify the degree of inlet distortion by the device. Preliminary inlet distortion tests were performed in Altitude Engine Test Facility(AETF) of Korea Aerospace Research Institute(KARI) and results showed that the inlet distortion simulating device could be used in simulating various inlet distortion cases.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.78-83
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• 2014

A special part such as a flow passage opening device is required to prevent the disconnection of fuel transfer in a pressurized fuel tank. To meet this requirement, the device utilizing an acceleration follow-up technique was invented. RecurDyn, a dynamic analysis tool, is introduced in this article to predict the device's performance and to determine parameters affecting it. In the analysis, it is shown that balancing weights can open the passage in accordance with fuel position.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.416-423
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• 2012

Liquid acquisition device in the liquid propellant supply system is required to protect entrance of gas bubble into the propulsion system. The device exploits the capillary effect of micro-sized poles in a screen and supplies pure liquid-phase propellant to the propulsion system. The bubble point is the most important performance parameter in the design of a liquid acquisition device. In this paper, performance parameters affecting the bubble point are identified through literature survey, in order to develop the experimental setup for the bubble point measurement.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.616-617
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• 2010

Nemerical analysis was carried out for a patented SNECMA modulatable thrust device. By adopting aerospike-like nozzle and a moving needle, proposed modulatable thrust device are capable of delivering optimal thrust according to the altitude.

• Journal of Ship and Ocean Technology
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• v.9 no.2
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• pp.11-20
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• 2005

A mixed-flow pump is largely applied for waterjet propulsion in high-speed vessels because of excellent cavitation performance. For the present study, we analyze the performance of mixed-flow pump, which is composed of impeller and stator. The test device for a mixed-flow pump was installed in the test section in the KRISO cavitation tunnel. The performance tests of two mixed-flow pumps were carried out with the test device at various flow rates using various nozzles. The test results agree fairly well with the predicted results by commercial CFD code. The test device is available for verification of impeller performance together with CFD analysis

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.381-385
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• 2005

Recently, spacecraft technology trends can be expressed three words, i.e. 'faster, cheaper and smaller'. Among these systems, micro propulsion device is an essential component. Also micro nozzle is the most important part in the micro propulsion device. In case of cold-gas thruster, micro nozzle converts the stored energy in a pressurized gas into kinetic energy through expansion ratio. In this paper we report characteristics of micro nozzle with throat expansion ratio and ratio of specific heats. We measure thrusts using strain gauge based thrust measurement system. We can estimate the micro nozzle performance through experiments.