• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.99-103
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• 2017

As a development test of the 75-tonf LOx/Kerosene liquid rocket engine for KSLV-II first Stage Engine, hot firing test of 75-tonf engine are performed. The current status of development test on first stage 75-tonf engine system including combustion chamber, turbopump, gas generator, propellant supply system are presented. During the 75tonf engine test campaign, the development of startup sequence of LOx-Kerosene engine system, engine startup using pyrostarter, ignition of gas generator, steady operation and engine shutdown is successfully performed. As a passenger test during engine hot firing tests, Thrust Vector Control system (TVC) of the engine are also evaluated during engine hot firing test. The results of hot firing test of 75-tonf thrust engine system will be used for the design confirmation and performance evaluation of 75 tonf engine system for KSLV-II first Stage.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.436-442
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• 2012

In the process of liquid rocket engine design, obtaining method of the dynamic characteristics of engine should be emphasized typically to determine the control logic and algorithms of the throttle valves in the propellant feed pipeline. However, determining the dynamic characteristics of an engine through the autonomous test is very hard and laborious, so that the numerical approach is prevailing. In this study, using the previously developed dynamic analysis model of the engine around the steady state, we introduced a disturbance to this model, and obtained the dynamic response in the time domain. And by applying the well-known Levy method to this temporal response, we could deduce the transfer function of that system that can give us various information of engine and can be manipulated to design the control system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.8
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• pp.675-685
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• 2016

A research area on liquid rocket engine has been suggested. Downsizing through combustion pressure rise and low price are major issues to gas generator cycle engines. A very high pressure turbopump and material against oxidizer rich environment may be necessary technologies for staged combustion cycle engines. Integrated analysis saving computing time is the trend of rocket engine systems analysis area. Other important research topics are the methane engine for reusable booster to reduce the cost, 3D printing and materials for high temperature or oxidizer rich environment.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.148.2-148.2
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• 2012

2차 대전 이후 미국과 소련의 우주 경쟁으로 인해 로켓엔진에 대한 많은 발전이 이루어졌고 그 결과 새로운 엔진 사이클과 많은 종류의 추진제가 개발되었다. 냉전 후 많은 ICBM이 민간용으로 개조되었지만 대부분의 민간용 발사체는 연료로 케로신과 액체수소를 사용하고 있다. 아폴로 계획까지 우주개발 초창기에는 미, 소 양국 모두 케로신 엔진을 주축으로 사용하였으나 우주왕복선의 시대가 도래한 이후 미국에서는 수소엔진을 주력으로 사용하였다. 그러나 현재 우주왕복선이 퇴역한 이후 러시아의 도움을 받아 개발 혹은 수입된 케로신 엔진이 델타와 아틀라스에 사용되고 있다. 또한 최초의 민간발사체인 팰콘에도 멀린이라는 케로신 엔진이 적용되었다. 수소엔진 이후에 새로이 개발되고 있는 메탄엔진은 아직 실용화에는 이르지 못하였기 때문에 적어도 당분간은 케로신 엔진이 로켓엔진 분야를 선도할 것으로 보인다.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.1
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• pp.16-25
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• 2014

The system analysis and design program of the liquid rocket engine has been developed for preliminary conceptual design process. The program consists of modular programs analyzing the main thruster, the gas-generator, turbo-pumps, the turbine, pipes, valves and so on. Each module has been developed in order to estimate performance, weight, and shape parameters of the components. The results of them have been verified with experimental data or other programs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.12
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• pp.1055-1062
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• 2012

In this paper, the mathematical models and control algorithm of a thrust control valve were described as a precedent study on the design of thrust control algorithm for a liquid rocket engine (LRE). Numerical simulations were performed using a simplified simulation system of an LRE and the developed mathematical models were validated by comparison with the experimental results. Through these research, basic data were acquired for the development of a thrust control algorithm for a LRE.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.3
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• pp.9-19
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• 2009

Accurate thrust measurement is very important when developing an engine of propulsion system. Especially for a low thrust liquid rocket engine(LRE), accuracy of thrust is seriously affected by thrust measurement errors and thurst losses which are caused by propellant supply system. In this study, a new thrust measurement system is developed for accurate thrust measurement of a low thurst LRE by minimizing these effects. Its thrust measurement range is 150~1500N and the maximum error is below 10N. Also, a reliability appraisal technique is investigated to improve reliability and accuracy of the thrust measurement system.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.12
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• pp.1180-1185
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• 2008

In-house code which simulates the performance of pre-burner in staged-combustion liquid-fueled rocket engine was developed and demonstrated. Chemical reaction of pre-burner was modeled based on analytic algorithm of CEA (Chemical Equilibrium with Applications) and gas dynamics model was incorporated with it. Comparison results between in-house code and CEA have shown small relative errors except at very high or very low O/F ratio. Also the performance curve obtained by in-house code revealed that the calculated values follow the overall trend of real engine (RD-8) performance quite well and at steady-state operation, the deviation became very small.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.11-15
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• 2012

A rotordynamic analysis is performed for a 7 ton class turbopump applied to the third stage LRE(Liquid Rocket Engine) of the KSLV(Korea Space Launch Vehicle). Based on the heritage of the developed experimental 30 ton class turbopump and developing 75 ton class turbopump for the KSLV first and second stage LRE, the 7 ton class turbopump is designed as an one-axis rotor turbopump. Two rotor systems comprised of one oxidizer pump assembly and the other fuel pump-turbine assembly are connected each other using a spline shaft and operating at a design speed. Through the rotordynamic analysis, it is investigated that the turbopump acquires sufficient separate margin of critical speed as a sub-critical rotor.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1038-1047
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• 2009

The development process of a gas generator for a 30-tonf pump-fed space liquid rocket engine is described. Starting from the development of an injector, followed by subscale and full-scale test specimens, the development of LOx/kerosene fuel-rich gas generator has been concluded successfully. Various analytical methods have been utilized in the course of design and the performance requirements have been verified experimentally through ignition tests, combustion performance and stability assessment tests and duration tests. The gas generator has proven its workability and stability within a defined operation window of varying chamber pressure and mixture ratio and demonstrated compliance to the performance and life time requirements.