• Proceedings of the KIEE Conference
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• summer
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• pp.1319-1321
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• 2004

This paper presents a model and simulation for the korean type multi-propulsion system consisting of a gas turbine driven synchronous alternator coupled to a rectifier and dc-to-dc converter. The simulation modules include turbine system, alternator and rectifier, dc-to-dc converter, power management module. A modular, system level simulation of the propulsion system prototype is presented in order to confirm stability for loads with uncertain input impedances and uncertain control loop speeds.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.295-299
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• 2010

Recently, development and application of the condition monitoring and diagnostic system for improvement of durability and reliability and reduction of operating cost is generalized in the aircraft propulsion system. Especially, for reliable operation of the UAV which is flying in high altitude more than 40,000 ft for a long time an condition monitoring system to identify faults and degradations of its propulsion system should be needed. Therefore, this work proposes an on-line condition monitoring program using MATLAB/SIMULINK. In the development phase of the program, a engine signal generation module is used to simulate real engine measuring parameters instead of the real engine. The proposed on-line condition monitoring program was applied to a real turboprop engine to validate its application capability.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.1
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• pp.54-62
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• 2014

This study deals with the design and characteristics analysis on a linear synchronous motor (LSM) with a long stator and phase concentrated winding (PCW) to apply for a propulsion system such as a roller coaster for leisure facilities. First of all, the required propulsion force of LSM is computed and its design with double sided permanent magnets (PMs) and a phase concentrated winding is processed. The phase concentrated winding is composed of a module with each A, B, and C phase unlike an conventional concentrated winding (CW). It has an advantage of the installation and manufacture, compared to the conventional concentrated winding in the propulsion system for leisure facilities that have a long acceleration area and stator configuration placed on rail continuously. Thus, the design for the propulsion system and characteristics comparison between the phase concentrated winding and concentrated winding are carried out in this paper. Also, the analysis on dynamic characteristics is conducted to confirm the performance at operation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.929-932
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• 2011

We developed a valve actuator controller for thruster system. This thruster system has four actuators and the actuator use a BLDC motor. Controller was made based on system and control requirement. The controller is consist of power, control and Amp. The control module use a micro-controller which is TMS320F28335 of Texas Instruments. It works for digital PID control and CAN communication and system control. The amp module for three phase BLDC motor use IGBT.

• Journal of the Korean Society of Propulsion Engineers
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• v.23 no.4
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• pp.50-60
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• 2019

This paper introduces the development of a toolbox for the Space Shuttle Main Engine(SSME) based on MATLAB/Simulink. A mathematical model of rocket engine creation and validation can be a complex process, the development of a rocket engine toolbox simplifies this process, thereby facilitating engine performance optimization as well as new design development. The mathematical modeling of the SSME dealt with in this paper is formed by 32 first-order differential equations derived from seven governing equations. We develop the toolbox for the SSME classifying each module according to the engine components. Further, we confirm the validity of the toolbox by comparing the results of the simulation obtained using the toolbox with those obtained using the original simulation of the engine.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.271-273
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• 1993

One maglev vehicle is composed of 6 or 8 modules. Each module is composed of 4 staggered magnets attached to an aluminum bogie. In the view point of levitation control except propulsion-by LIM. 5 is the maximum degree of freedom to be controlled. But rolling control of the vhhicle depends on the bogie structure. We describe just anti-roll type bogie structure and 4 degree of freedom control is sufficient for levitation quality improvement. Multivariable pole-placement concept is used for controller design. Control experiment is performed on a specially designed test module as well as actual bogie system.

• Journal of the Korean Society of Propulsion Engineers
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• v.9 no.1
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• pp.35-45
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• 2005

Numerical study is carried out to investigate the effects of chemistry and thermal radiation on the rocket plume flow field at various altitudes. Navier-Stokes equations for compressible flows were solved by a fully-implicit TVD code based on the finite volume method. An infinitely fast chemistry module for hydrocarbon mixture with detailed thermo-chemical properties and a thermal radiation module for optically thick media were incorporated with the fluid dynamics code. The plume flow fields of a kerosene-fueled rocket flying at Mach number zero at sea-level, 1.16 at altitude of 5.06 km and 2.90 at 17.34 km were numerically analyzed. Results showed the plume structures at different altitude conditions with the effects of chemistry and radiation. It is understood that the excess temperature by the chemical reactions in the exhaust gas may not be ignored in the view point of propulsion performance and thermal protection of the rocket base, especially at higher altitude conditions.

• Journal of the Society of Naval Architects of Korea
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• v.58 no.4
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• pp.225-233
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• 2021

Conventional submarine propulsion batteries have mainly used lead acid batteries, which have proved relatively safe, but in recent years, research on mounting lithium-ion batteries to improve the underwater operation capability of submarines is underway in advanced countries such as Japan. Korea has world-class technology in the development of electric vehicles and lithium-ion batteries for energy storage, but fire safety accidents continue to occur in electric vehicles and energy storage lithium-ion batteries. In order to mount the lithium-ion battery in a submarine, it is necessary to check the safety as well as whether the performance is improved compared to the lead acid battery. Through the charge/discharge experiment of this lithium-ion battery module unit, it was possible to measure how much performance was improved compared to the lead acid battery. Safety tests were conducted on the lithium-ion battery module assuming that it was mounted on a submarine, and it was confirmed that safety was secured when applied to a submarine. Since many modules are mounted on actual submarines, it has been confirmed that it can be applied to submarine systems by simulating charge/discharge characteristics through Hardware-in-the Loop(HILS). Through the results of this study, the application of lithium-ion batteries to submarines is expected to significantly improve the sustainability of underwater operations.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.167-169
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• 2010

Electronic control units for propulsion systems are devices which compute control algorithm by processing the systems' internal sensor signals. Due to the effect of transmission between sensors and a control unit, previous analog systems have drawbacks of signal attenuation and susceptibility to noises. However, a digital sensor can be less influenced by the electrical cable line as it includes sensor, AMP, and AD converter in one module. In addition, it can reduce the process time for control algorithm because extra S/W filtering process is not needed. The current study shows how to process signals for an electronic control unit using digital sensors.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.6
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• pp.59-67
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• 2014

Acceptance level random vibration and life firing test for development model of 1 N-class monopropellant thruster have been performed. From the results of random vibration, the natural frequency of the dual thurst module composed of 1 N-class development model thrusters was higher than the part level requirement(>100 Hz) and the structural robustness was verified. Thrust decrease of steady sate was below 7% and thrust instability was within ${\pm}5%$ in the life firing test using over 20 kg propellant throughput. The computerized tomography for catalyst bed showed a less than 7% of catalyst loss and it revealed the design appropriateness of the current thruster development model.