• 대한공업교육학회지
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• v.41 no.2
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• pp.134-150
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• 2016

This study has analyzed the subjects of transportation technology problem solving activities at Energy and Transportation Technology unit in the 12 kinds of middle school Technology Home Economics textbooks of the 2009 national revised curriculum. An analysis frame was developed with systems and environmental mediums which are common elements of transportation and the subjects were analyzed. As a result of this study, first, 8 kinds of subjects among 20 subjects in analysis frame were suggested in the textbooks. Second, according to the environmental, there are 13 terrestrial activities, 2 atmospheric activities, and 1 marine activity in the textbooks. However, there is no space related activity. Third, according to the system, there are 13 activities for the structure, 12 activities for the propulsion and suspension system, 5 activities related to the control system, and 1 activity regarding guidance system. Fourth, there are 4 kinds of problem solving activities depending on categorizing result of the analysis of the activities.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.8
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• pp.640-647
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• 2014

Infrared signature of aircraft exhaust plume is the critical factor for aircraft survivability. To improve the military aircraft survivability, the accurate prediction of infrared signature for the propulsion system is needed. The numerical analysis of thermal fluid field for nozzle inflow, free stream flow, and plume region is conducted by using the in-house code. Weighted Sum of Gray Gases Model based on Narrow Band with regrouping is adopted to calculate the spectral infrared signature emitted from aircraft exhaust plume. The accuracy and reliability of the developed code are validated in the one-dimensional band model. It is found that the infrared radiant intensity is relatively more strong in the plume through the analysis, the results show the different characteristic of the spectral infrared signature along the temperature, the partial pressure, and the species distribution. The continuous spectral radiant intensity is shown near the nozzle exit due to the emission from the nozzle wall.

• Journal of recreation and landscape
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• v.6 no.2
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• pp.27-36
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• 2012

This study, presents the details of a propulsion system for a systematic approach to the remodeling of rural villages as part of the pilot project that will be implemented in 2013. Studies on remodeling rural villages have focused mainly on various concepts of remodeling purposes and functions, and on the size and allocation standards of the facilities, such as rural houses, village rest areas, or public facilities. Thus, research is required on the establishment of a plan to restructure rural spaces and suggestions regarding the standards applicable at the local sites. This study employed an upward access system to prepare for the remodeling project and encourage the local residents' participation. As a result, the local residents voluntarily participated in drawing up a comprehensive plan for the village maintenance settings and forms, and for making the arrangements, by discussing the pros and cons of the plan, or through the forum. Based on this result, the local government examined the project in terms of its specifics, size, timing, budgetary appropriation, and anticipated results in order to implement the project, and also provided aid from the field experts to review the plan for the space and facility plans, and the legal system to establish the remodeling plan for the rural villages. Thus, this study attempts to contribute toward improving the quality of the rural villager's lives through a comprehensive remodeling of the whole rural village, not through an individual remodeling method.

• Journal of Aerospace System Engineering
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• v.18 no.1
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• pp.53-63
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• 2024

Adopting an engine igniter with high efficiency and ignition performance is essential for reliable operation of liquid rocket engines. In this study, we developed a spark torch igniter for a 450 N-scale methane-oxygen liquid rocket engine by conducting numerical analyses, igniter manufacturing and validation. Specifically, we conducted a parametric study for maximizing the enthalpy at the igniter exit, specifically by adjusting the mass flow rate, nozzle area ratio, fuel-oxidizer mixture ratio, and the igniter length-to-diameter. The heat transferred via the igniter nozzle exit was computed using 3-dimensional numerical simulations. We also manufactured and tested the igniter based on a deduced design to confirm ignition performance of the designed spark torch igniter. The igniter developed through this study could contribute to the development of practical propulsion systems such as upper-stage engines of small launch vehicles.