• Nuclear Engineering and Technology
• /
• v.47 no.6
• /
• pp.678-699
• /
• 2015

Although the harsh space environment imposes many severe challenges to space pioneers, space exploration is a realistic and profitable goal for long-term humanity survival. One of the viable and promising options to overcome the harsh environment of space is nuclear propulsion. Particularly, the Nuclear Thermal Rocket (NTR) is a leading candidate for nearterm human missions to Mars and beyond due to its relatively high thrust and efficiency. Traditional NTR designs use typically high power reactors with fast or epithermal neutron spectrums to simplify core design and to maximize thrust. In parallel there are a series of new NTR designs with lower thrust and higher efficiency, designed to enhance mission versatility and safety through the use of redundant engines (when used in a clustered engine arrangement) for future commercialization. This paper proposes a new NTR design of the second design philosophy, Korea Advanced NUclear Thermal Engine Rocket (KANUTER), for future space applications. The KANUTER consists of an Extremely High Temperature Gas cooled Reactor (EHTGR) utilizing hydrogen propellant, a propulsion system, and an optional electricity generation system to provide propulsion as well as electricity generation. The innovatively small engine has the characteristics of high efficiency, being compact and lightweight, and bimodal capability. The notable characteristics result from the moderated EHTGR design, uniquely utilizing the integrated fuel element with an ultra heat-resistant carbide fuel, an efficient metal hydride moderator, protectively cooling channels and an individual pressure tube in an all-in-one package. The EHTGR can be bimodally operated in a propulsion mode of $100MW_{th}$ and an electricity generation mode of $100MW_{th}$, equipped with a dynamic energy conversion system. To investigate the design features of the new reactor and to estimate referential engine performance, a preliminary design study in terms of neutronics and thermohydraulics was carried out. The result indicates that the innovative design has great potential for high propellant efficiency and thrust-to-weight of engine ratio, compared with the existing NTR designs. However, the build-up of fission products in fuel has a significant impact on the bimodal operation of the moderated reactor such as xenon-induced dead time. This issue can be overcome by building in excess reactivity and control margin for the reactor design.

• 한국전산유체공학회:학술대회논문집
• /
• 2008.03b
• /
• pp.428-431
• /
• 2008

Korea Aerospace Research Institute(KARI) is achieving the Korea Space Launch Vehicle(KSLV) program according to National Space Technology Development Program. KSLV-I will be composed to liquid propellant(first stage) and solid propellant(second stage) propulsion system. The propulsion system of KSLV-I second stage is solid kick motor with high expansion ratio and its starting altitude is 300km high. In order to verify the performance of upper stage propulsion system designed to operate in the upper atmosphere, test facility which can simulate high altitude is needed. High Altitude Simulation Test Facility is composed to Thrust Measurement System, Control & Measurement system, Diffuser, SKID for cooling water supply to diffuser, CCTV, fire protection system and so on. This paper introduces TMS adapted to High Altitude Simulation Test for KSLV-I Kick Motor Development and results of hot firing test for its performance verification.

• Journal of the Society of Naval Architects of Korea
• /
• v.61 no.1
• /
• pp.19-28
• /
• 2024

Environmental regulations are becoming more stringent in response to climate change, especially concerning marine pollution caused by ship emissions. Large ships are adjusting by integrating technologies to reduce pollutant emissions and transitioning to eco-friendly fuels such as low-sulfur oil and LNG. However, small ships face space constraints for installing LNG propulsion systems and the risk of power depletion with pure electric propulsion. Consequently, there's growing interest in researching hybrid propulsion methods that combine electricity and diesel for smaller vessels. Hybrid propulsion systems utilize diverse energy sources, requiring an effective method for evaluating their efficiency. This study proposes employing Bond graph modeling to comprehensively analyze energy dynamics within hybrid propulsion systems, facilitating better understanding and optimization of their efficiency. Modeling of the ship's energy system using Bond graphs will be able to provide a framework for integrating various energy sources and evaluating their effects.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2006.05a
• /
• pp.17-22
• /
• 2006

Anhydrous hydrazine and its methyl derivatives MMH and UDMH have been safety used as monopropellant and bipropellant fuels in thousands of satellites and expendable launch vehicles. Since KOMPSAT program, We have been developing skills on the hydrazine propulsion system for several years. This paper presents an overview of the hydrazine for the space application - propellant overview, material compatibility, handling cautions and the future of hydrazine systems.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.11
• /
• pp.1640-1646
• /
• 2013

Conventional power conversion unit that is a major part of the propulsion system has applied GTO thyristor as a switching semiconductor device of main circuit since introduction of the 8200 electric locomotive. But problem that quick maintenance is difficult and its cost is increasing occurs because major components of the power conversion unit are slowly discontinued. To solve these, in this paper, it was analyzed the response characteristic of the propulsion system modeling of the 8200 electric locomotive using IGBT which is applied recently to ensure propulsion control technology. As results of response for a Propulsion system modeling, it show that a power conversion unit is controlled by PLL(Phase-locked loop) and SVPWM(Space Voltage PWM) respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.35 no.10
• /
• pp.948-956
• /
• 2007

It is important during FSD(Full Scale Development) period to verify whether the aircraft system function meets the aircraft requirements and functional performance. Especially, the functionality of the integrated propulsion system should be verified to evaluate the compatibility with aircraft. Various flight tests such as the engine airstart test, the engine horsepower extraction test, the backup throttle functionality test had been performed to evaluate the engine/aircraft compatibility with T-50 during FSD period. Through such flight tests, it was confirmed that the propulsion system of T-50 was properly designed and installed to the aircraft. This paper shows description on each flight test item, test procedure and test results. It is expected that this paper could be a reference for preparing the propulsion flight test in other aircraft developments.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.1180-1183
• /
• 2017

The Propulsion System Test Complex (PSTC) is constructed for developing KSLV-II in the Naro space center. The KSLV-II uses LOX for oxidizer and oxidizer filling algorithm is developed for supplying oxidizer to KSLV-II. This paper introduces oxidizer filling algorithm.

• International Journal of Aeronautical and Space Sciences
• /
• v.9 no.2
• /
• pp.64-70
• /
• 2008

The UAV propulsion system that will be operated for long time at more than 40,000ft altitude should have not only fuel flow minimization but also high reliability and durability. If this UAV propulsion system may have faults, it is not easy to recover the system from the abnormal, and hence an accurate diagnostic technology must be needed to keep the operational reliability. For this purpose, the development of the health monitoring system which can monitor remotely the engine condition should be required. In this study, a fuzzy trend monitoring method for detecting the engine faults including mechanical faults was proposed through analyzing performance trends of measurement data. The trend monitoring is an engine conditioning method which can find engine faults by monitoring important measuring parameters such as fuel flow, exhaust gas temperatures, rotational speeds, vibration and etc. Using engine condition database as an input to be generated by linear regression analysis of real engine instrument data, an application of the fuzzy logic in diagnostics estimated the cause of fault in each component. According to study results. it was confirmed that the proposed trend monitoring method can improve reliability and durability of the propulsion system for a long endurance UAV to be operated at medium altitude.

• Publications of The Korean Astronomical Society
• /
• v.22 no.4
• /
• pp.169-175
• /
• 2007

The international cooperation project CIBER (Cosmic Infrared Background ExpeRiment) is a rocket-borne instrument, of which the scientific goal is to measure the cosmic near-infrared extra-galactic background to search for signatures of primordial galaxy formation. CIBER consists of a wide-field two-color camera, a low-resolution absolute spectrometer, and a high-resolution narrow-band imaging spectrometer. Currently, all the subsystems have been built, and the integration, testing, and calibration of the CIBER system are on process for the scheduled launch in June 2008.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.2
• /
• pp.89-95
• /
• 2003

Propulsion system of the current developing satellite is roughly composed of propellant tank and four major modules. Each module prevides the pulse momentum for spacecraft attitude control, filling/draining of propellant and pressurant, propellant filtering, and the change of flow passage in the spacecraft emergency situation, respectively. These modules will be fixed on the propulsion platform with their suitable mounting brackers, so the brackets shall be designed sufficiently to support a function of the modules under launch environment and on-orbit condition. The purpose of this article is to check if all the bracket designs satisfy the defined structural requirements through finite element analysis, and then to verify structural safety.