• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2007.11a
• /
• pp.289-292
• /
• 2007

Performance of a dual mode ramjet engine based on the sensitivity analysis of design parameters (the gap between cowl and inlet spike and combustor length) was analyzed from the view points of aerodynamics and thermodynamics. A dual mode engine performing from supersonic to hypersonic (Mach no. 2 to 6) was designed in a proposed flight envelop. The design method and result were comparable to the results of the previous study, Hyperion RLV, and the CFD calculation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.928-929
• /
• 2017

A 75 ton class liquid rocket engine has been developed for KSLV II. Ground firing tests of the rocket engine were conducted to characterize and quantify its structural vibration under combustion testing environments. In this study, evaluation of dynamic response characteristics of the engine system was presented to verify its structural integrity and structural design during ground firing tests.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2017.05a
• /
• pp.1104-1107
• /
• 2017

In this paper, we focused on Analytic Hierarchy Process(AHP) as an efficient means of decision-making on the major issues that may arise during the liquid rocket engine development, reviewed the validity and applicability of the AHP through the problem of selecting the propellant of the liquid rocket engine.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2004.10a
• /
• pp.235-238
• /
• 2004

In the present study, the stability of turbopump through the rotor dynamics was analyzed with the location analysis method of the pole of characteristic equation for stability analysis of LRE and the design guideline for turbopump was presented according to design requirements of the LRE.

• Journal of Korea Society of Industrial Information Systems
• /
• v.17 no.4
• /
• pp.71-85
• /
• 2012

This paper aims to develop an event-driven failure analysis and prognosis system that is able to monitor ship status in real time, and efficiently react unforeseen system failures. In general, huge amount of recorded sensor data must be effectively interpreted for failure analysis, but unfortunately noise and redundant information in the gathered sensor data are obstacles to a successful analysis. This paper therefore applies 'Equal-frequency binning' and 'Entropy' techniques to extract only important information from the raw sensor data while minimizing information loss. The efficiency of the developed failure analysis system is demonstrated with the collected sensor data from a marine diesel engine.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.191-200
• /
• 2020

Tracked military vehicles are operated under harsher conditions and climates than ordinary vehicles, and the components require high degrees of reliability and durability. A diesel engine is the main power generator, and when the vehicle breaks down, there is a high possibility of causing a large-scale accident. Therefore, analyzing the cause of engine failure can be important for preventing similar cases that may occur. In this study, we clarified the mechanism of engine failure according to an overhaul test, hardness measurement, and an analysis of the fracture surface. The overhaul test confirmed that a bolt was separated from the connecting rod (number 4). In addition, the hardness measurement results of the connecting rod bolt conformed to the standard, and it was found that the bolt fracture was ductile fracture through an analysis of the fracture surface. Based on the results, it was concluded that damage to a diesel engine of a tracked military vehicle was caused by separating and damage caused by loosening of the connecting rod bolts, resulting in cascading damage. The results of the study could be used as reference examples and could be useful for another study on engine failure analysis.

• Proceedings of the KIEE Conference
• /
• 1987.07b
• /
• pp.1203-1205
• /
• 1987

가솔린 엔진용 전자 제어 에뮬레이션 시스템은 엔진의 운전 상태를 알려 주는 각종 센서로 감지한 정보를 A/D변환기를 통해 마이크로프로세서에 입력시키고, 이 정보를 이용하여 운전 상태를 분석한 후 엔진이 푤요로 하는 연료량, 점화시기, 배기가스의 재순환량, 공회전수 등을 전자적으로 제어하여 엔진의 최적제어를 실현시킴으로서 연료소비율 및 배기가스 중 공해물질 함량을 감소시키기 위한 장치이다.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.32 no.3
• /
• pp.310-315
• /
• 1996

엔진 배기가스의 동력과 유량이 배기행정의 직전 단계에서 관찰되었다. 배기가스 양을 적당히 조정함으로써 터보 과급의 입구 압력을 증가시킬 수 있었으며 엔진의 흡기, 소기 및 배기과정에서 가스질량과 엔진의 동력, 그리고 터보과급 효과도 감소하였다. 터보 과급장치를 기하학적으로 적절화시킴으로써 싸이클의 동기화 및 동력의 효율이 고려된 열교환 과정의 효율 기준도 제기되었으며 디젤엔진의 연소싸이클을 재수정하는 과정과 터빈의 동역학적 특성도 제시되었다.

• Proceeding of EDISON Challenge
• /
• 2016.11a
• /
• pp.9-14
• /
• 2016

버드 스트라이크는 항공기 안전에 큰 위협을 주고 있다. 새를 막기 위하여 공항에서 여러 가지 방법들을 이용해 새를 쫓고 있지만 임시방편인 경우가 많거나 근본적인 방법은 아니다. 본 연구에서는 이러한 버드 스트라이크를 막기 위하여 새를 막는 장치를 엔진 흡입구에 장착하고, 이 흡입구가 엔진 흡입구의 성능에 어떠한 영향을 주는지 알아보려고 한다.

• The Journal of Information Technology
• /
• v.1 no.2
• /
• pp.55-63
• /
• 1998

본 논문은 웹 상에서 하이퍼텍스트 문서의 정보 검색에 있어서 검색에 요구되는 질의어에 따른 검색 결과가 주제에 따른 관련성을 측정하며, 하이퍼텍스트 문서가 링크되는 문서 상호간의 유사성에 대하여 정량화를 시도함으로써 검색 엔진의 성능분석을 제시한다.