• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.10a
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• pp.87-91
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• 2004

It is definitely required to control dispersion of the rocket engine performance in order to accomplish the mission of launch vehicle successfully. We performed the dispersion analysis of gas generator cycle LRE (liquid rocket engine) accompanied with ANASYN. As a result, the vacuum thrust dispersion of the engine was $+5.34\%,\;-5.27\%$ and the mixture ratio deviated $+9.07\%,\;-9.82\%$ from the nominal value due to the errors of components and engine inlet condition of propellants. By applying the gas generator regulator only, the dispersion of the engine performance increases. Error in turbine efficiency is the most influential factor to the dispersion of engine performance.

• Proceedings of the KIEE Conference
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• summer
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• pp.1103-1105
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• 2004

현대 도시인들에게 전력의 신뢰성있는 공급은 당연시되고 있다. 그러나, 2002년 캘리포니아에서 있었던 대규모의 정전 사고는 불안정한 전력의 공급이 현대 문명 생활에 있어서 얼마나 큰 영향을 끼치며, 개별적인 보완 전력 공급의 중요성에 대해서 일깨워주는 계기가 되었다. 지금까지 이러한 전력 공급의 중단에 대한 주요 대비책으로서 비상용 엔진 발전기 시스템은 보조 전원의 중요한 역할을 해왔다. 여기에서 더 높은 효율과, 첨두 부하 절감의 기능, 그리고 전력 계통과의 Co-generation 기능을 가지는 고기능의 제어 시스템에 대한 수요가 증대되어지고 있는 상태이다. 본 논문에서는 다수 비상용 발전기들의 병렬 운전 및 전력 계통과의 연계 운전을 지원하는 고기능의 디지털 전력제어 시스템과 운전 지원을 위한 감시 제어 시스템에 대해 소개한다.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.233-234
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• 2016

본 논문에서는 소형 어선의 전기 시스템을 DC 마이크로그리드의 관점에서 설계하고, 선박의 동력원인 엔진-발전기를 가변속 제어함으로써 선박 전력 계통의 효율을 개선하고자 한다. 선박 전력 계통은 물리적으로 육지 계통과 분리된 마이크로그리드의 형태를 갖추고 있다. 때문에 소형 기계 추진 어선의 경우, 추진을 위한 엔진뿐만 아니라 추가적으로 선내 전력을 공급하기 위한 엔진-발전기를 갖출 필요가 있다. 이에 반해 전기 추진 어선은 하나의 엔진-발전기 세트로 추진과 선내 전력 공급이 모두 가능하다. 하지만 어선이 정지 상태에서 조업을 할 때에 전력 부하량이 작기 때문에 엔진의 저부하 운전 문제가 발생한다. 본 논문에서는 이를 해결하기 위하여, DC마이크로그리드를 어선에 적용하여 엔진 가변속을 적용하고자 한다. 통상적으로 20% 내외의 부하율로 운용되는 엔진에 가변속 제어를 적용하면 20% 이상의 연비 개선 효과를 기대할 수 있다. 이러한 DC마이크로그리드 어선의 연비 개선 효과를 항해와 조업으로 구분하여 시뮬레이션을 통해 예측하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.6
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• pp.26-34
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• 2007

The efforts to develop high performance aircraft engines are successively progressed with development of recent technology. The reliability of individual parts and the safety of engine systems are reduced if high efficiency components, high strength materials, and precise controls are applied to the engine with complexity to increase engine performance. In this paper, the regulation requirements and assessment technique for aircraft engine safety are considered, and the result of safety assessment on a turbine case cooling system of high efficiency turbofan engine is presented.

• Journal of the Korean Society of Propulsion Engineers
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• v.1 no.1
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• pp.24-32
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• 1997

A nonlinear dynamic simulation of a small gas turbine engine was performed by using DYNGEN program with various environmental conditions. It was observed that the effect of the bleed air flow rate changed to overall engine performance. The real time linear model which was a function of engine rotor speed was resulted to be close to nonlinear simulation results. For optimal LQR controller, it was considered only fuel flow rate or both fuel flow rate and bleed air rate as inputs. In the comparison of both results, the LQR controller with multi input had better performance than that with single input.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.04a
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• pp.55-60
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• 1997

A nonlinear dynamic simulation was performed by using DYNGEN program with various environmental conditions. It was observed that the effect of the bleed air flow rate changed to overall engine performance. The real time linear model which was a function of rpm was resulted to be close to nonlinear simulation results. For optimal LQR controller, it was considered only fuel flow rate or both fuel flow rate and bleed air rate as inputs. In the comparison of both results, the LQR controller with multi input had better performance than that with single input.

• 전기의세계
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• v.44 no.10
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• pp.33-39
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• 1995

본고에서는 능동 소음 제어 기법의 기본 개념을 소개하고, 1차원 음장에서의 능동 소음 제어에 관한 응용 예로 공조 시스템 및 엔진의 배기관(exhaust)에서의 능동 소음 제어 시스템과 3차원 공간에서의 응용 예로 자동차 내부에서의 능동 소음 제어에 관한 최근의 연구 결과를 소개하고, 현재의 연구동향과 앞으로의 전망을 논하고자 한다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.174-177
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• 2007

In this work, we researched static and dynamic characteristics concern to hydraulic regulator control process and parameter setting, which is used on liquid rocket engine regulation. The hydraulic regulator of 8K14 "SCUD" 9D21 engine is analyzed and on the basis of the developed mathematical modeling the analysis of response time and certification on automatic control accuracy is carried out. In this process, we find out specific design configuration of needle valve flow section that effects on pressure regulation performance.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.11a
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• pp.129-132
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• 2008

For the development of the 30tonf level LOx/kerosene liquid rocket engine, turbopump-gas generator closed-loop coupled tests are performed. To simulate engine operation conditions, combustion chamber was substituted by flow control orifices. In simulated engine system operation environment, chill-down procedure, startup characteristics, nominal operability of turbopump+gas generator coupled Test Plant are confirmed. Turbopump and gas generator are confirmed to operate well in simulated engine environment. The control system for regulating power and mixture ratio of Test Plant are also successfully confirmed.

• The Journal of the Acoustical Society of Korea
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• v.11 no.4
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• pp.31-35
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• 1992

Cavity resonances are caused by combustion such as the rapid of pressure rise that occurs from knock in high power gasoline engines. These resonances generally occur at frequencies greater than 5KHz. Analysis of these resonances is important for knock control system design in high power gasoline engines. In this paper, in order to design knock control system for the high power gasoline engine, knock phenomena that occur in chamber were analized theoretically and resonance frequencies of knock signals were predicted. Also, experiments were performed using Soupe x-engine and non-resonance type knock sensor of Bosch co. in Germany. In the result, good agreement was obtained between theoretical prediction and experimental observation.