• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.4
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• pp.64-71
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• 2022

For the development of an improved upper-stage engine, research on a staged combustion cycle liquid rocket engine is in progress. A cold flow test, ignition test, and combustion test plans were established and performed to develop reignition combustion technology. In order to solve the problem of purge gas flowing into the fuel line, which may cause cavitation in the turbo pump during reignition, the test results of each stage were analyzed. Based on the analysis results, the purge gas inflow problem was solved by reducing the overlapping time between the operation of the bubble removal valve and the opening of the purge valve and the engine fuel valve. Based on this, the reignition combustion test was successfully performed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1999.10a
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• pp.19-19
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• 1999

KSR 3단 AKM Motor Case를 개발하기 위해 추진기관 경량화에 가장 유리하고 비강도 및 비강성이 뛰어난 복합재 연소관을 고려하여 직경 300mm급의 축소형 모델을 선행 개발하였다. Netting 이론에 의해 연소관 두께를 결정하고 체적을 최소화 하기 위해 구형으로 연소관 형상을 설계하였다. 연소관을 제작하기 위한 맨드렐은 분리, 조립식으로 설계, 적용하였고 연소관 기밀 유지 및 추진기관 연소시 연소관을 보호하기 위한 삭마성 재료로 EPDM base의 고무 내열재 조성을 개발하였다. 고무 내열재는 맨드렐 위에 적층하고 Vacuum bagging 상태로 Autoclave에서 가황하여 적용하였다. 국내 최초로 Prepreg를 사용하는 Dry process로 고무 내열재가 적층된 맨드렐 위에 Winding하고, Vacuum bagging 상태에서 경화하여 연소관을 제작하였으며, 이 때 사용한 Carbor/Epoxy Perpreg 재료의 기계적 성질 및 열특성 시험을 병행하였다. 제작된 연소관은 수압 시험을 통하여 구조적 안정성을 입증하였고, NDT 검사를 통해 재료간 계면 상태를 분석하였다. 시험이 끝난 연소관은 향후 점화기 개발을 위하여 점화제 종류 및 약량을 변경하여 점화 시험을 수행하여 점화기 개발을 위한 기초 데이터를 확보하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.5
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• pp.48-56
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• 2009

The auto-ignition tests of hybrid rockets with the concentrated hydrogen peroxide as an oxidizer were presented. Auto-ignition was successfully demonstrated by injecting decomposed gases from $H_2O_2$ into paraffin or polyethylene fuels. In addition, restart and instant ignition were realized with this rocket. For stable combustion, a higher $L^*$ value was required for the paraffin combustion compared with PE. On the other hand, much faster response time was demonstrated in case of a paraffin, which was 13 and 30 ms at ignition delay and rise time respectively.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.499-502
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• 2009

The auto-ignition tests of hybrid rockets with the concentrated hydrogen peroxide as an oxidizer were presented. Auto-ignition, restartability, and instant ignition were successfully demonstrated by injecting decomposed gases from $H_2O_2$ into paraffin or polyethylene fuels. In addition, much faster response time was demonstrated in case of a paraffin, which was 13 and 30 ms at ignition delay and rise time respectively.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.90-95
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• 2006

For single engine application like T-50, advanced supersonic jet trainer, airstart capability is very important. This paper presents the results of airstart tests performed to verify T-50 airstart capability for various flight condition. The tests include spooldown, APU assisted and auto-relight airstart tests. Except for the auto-relight tests T-50 engine was successfully restarted for all airstart tests. After modifying FADEC flameout detection schedule, auto-relight tests also were successfully demonstrated. Through T-50 engine airstart tests excellent T-50 airstart capability was validated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.7-14
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• 2004

The metal halide lamps are now widely used in the application and commercial lighting due to their attracting properties such as good color rendering and high efficiency. But, they have a serious problem of acoustic resonance using high frequency operation and they need a high voltage to ignite. So, they have not been applied to indoors. Over the past few years, a considerable number of studies have been conducted on the electronic ballast with hot restarting and resonance phenomenon. But, Very few attempts have been made at adaptive ignition method according to lamp state. In this paper is proposed electronicballast for metal halide lamps with an igniter for adaptive ignition. The proposed electronic bllast can generate a different ignition voltage according to the arc tube state.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.11a
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• pp.603-607
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• 2011

Structure of flashback and reignition occurring near flameholder was experimentally investigated in a model combustor with V-gutter flameholder. The combustor has a long duct shape with cross section of $40{\times}40mm$ and City Nature Gas(CNG) were used as fuel. Measurements of chemiluminescence with high speed camera was used for visualization of flame structure. In the lean case, flashback distance depend on equivalent ratio. New flame occurred at the front tip of flameholder when flashback. Flashback flame moved toward downstream direction of combustor because mixture flow velocity had increased, and then re-ignition was caused by entering flow into recirculation zone that is formed behind the flameholder.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.3
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• pp.41-48
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• 2008

One of main functions of the firing control system applied to a rocket propulsion test has been to provide electric current for ignition of a solid rocket motor. This paper describes the design and implementation of an enhanced firing control system for ground propulsion test that can also control and verify various types of squib events and flight sequences.

• Journal of Energy Engineering
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• v.18 no.3
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• pp.163-168
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• 2009

This paper describes the homogeneous charge compression ignition (HCCI) engine for a new concept. HCCI engines are being considered as a future alternative for diesel and gasoline engines. HCCI engines have the potential for high indicated thermal efficiency under part load and very low NOx emissions. The objective of this paper is to clear the effects of exhaust gas recirculation (EGR) rate on the HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine This work has been run with propane and butane fuels at a constant speed.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.6
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• pp.26-37
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• 2011

A 75-tonf-class LRE(liquid rocket engine) thrust chamber with ablative material for technology demonstration was manufactured on the basis of development technologies of 30-tonf-class LRE. Hydraulic characteristics of the thrust chamber were examined through cold flow test and ignition test of low flow condition. Test result showed that hydraulic function was good. Side ignition method with igniter ring also showed a fine function of ignition in operating ways of static condition. But a close review is required to understand the phenomena of generation and extinction of specific frequencies showed in dynamic characteristics ways. To achieve these, a large combustion test facility which is capable of performing combustion test at design condition of the 75-tonf-class thrust chamber should be constructed as soon as possible.