• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2000.11a
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• pp.22-22
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• 2000

고체 추진제에서 연소실 압력이 급격히 변하는 비정상 상태에서의 연소 특성은 정상 상태와 다른 경향을 보인다. 고체 추진 시스템에서 안정적이고 필요한 성능을 얻기 위해서는 이러한 비정상 상태에서 일어나는 현상에 대한 예측이 필요하다. 고체 추진제에서 비정상 연소는 크게 두 가지 경우에 나타나게 된다. 그 중 하나는 소염을 위하여 연소실내 압력강하가 일어나는 경우이며, 다른 하나는 점화 후 압력이 상승하는 경우이다. 급격한 압력 강하로 인한 고체 추진제의 소염에 대하여 그 동안 많은 연구들이 진행되었다.(중략)

• The Journal of the Acoustical Society of Korea
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• v.15 no.4
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• pp.105-112
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• 1996

A linear acoustic analysis for baffled rocket combustion chambers has been developed. This study provides the comprehensive theoretical background for the baffle as one of the stabilizing devices in a liquid rocket propulsion system. Several specific effects of baffles are presented as mechanisms by which baffles eliminate instability. Included are longitudinalization of transverse waves inside baffle compartments, severe restriction of velocity fluctuations near the injector face, and decreased normal mode frequency of the chamber.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.3
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• pp.48-55
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• 2014

In present study, design and hot fire tests of the pryostarter are conducted. To prevent the turbopump RPM overshoot, regressive mass flow rate profile is applied. Sudden decrease of the mass flow rate at the end of the propellant burning is realized as well. Firing test results show good agreements with the design requirements. Through the study with ignition substance variations, combustion products and ignition performances are improved.

• Journal of Korean Institute of Fire Investigation
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• v.9 no.1
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• pp.79-89
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• 2006

본 연구는 2004년 10월 3일 03시 29분경 전북 00시 00동 지리산 흑돼지 정육점에서 발생한 화재현장을 대상으로 화재조사 및 감식을 하여 그 원인을 규명하고자 하였다. 조사 결과 안쪽방과 매장 사이에 있던 냉장고가 심하게 소훼 되었고, 점포와 안방 출입문 부위를 중심으로 가장 심한 탄화상태를 보이는 것으로 발화지점으로 보이며, 점포 내 휴게공간에서 발화하여 점포내부와 화장실을 통해 연소 확대되었음을 확인하였다. 한편, 발화원인으로는 전기적원인, 가스 난방기구 및 담뱃불 등 미소화원 등에 의한 발화 가능성의 특이점이 보이지 않으며, 휴게공간에서의 급격한 연소현상, 폭발 후 화재로 진전된 흔적, 바닥의 가연성액체에 의한 연소흔적 등으로 보아 방화의 가능성이 높다. 화재는 휴식공간입구 우측 큰 교자상과 밑의 작은 교자상 밑, 그 주위에 연소매개체로서 등유를 뿌린 상태에서 휴대용가스렌지를 이용 방화한 것으로 추정된다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.803-810
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• 2017

the liquid oxygen transitions to a supercritical state, causing rapid changes in properties and pseudo boiling in supercritical combustion. the combustion reaction operating in a supercritical state depends on the turbulence diffusion caused by difference of density, therefore, a study of the diffusion flow and pseudo boiling is required. Many researchers have studied these phenomena in the supercritical combustion, but A case study by various variables is inadequate. In this study, the flow field and flame structure were investigated numerically by changing the recirculation flow and liquid oxygen core length through oxygen-fuel ratio(O/F), combustor diameter and recess ratio at supercritical pressure condition.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.8
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• pp.684-691
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• 2015

A sudden increase in combustion pressure is observed in the ducted rocket combustion test equipped with pipe shaped and converging nozzle exhaust tubes. This study aims to understand the physical mechanism of abrupt change in combustion pressure using thermal choking in the exhaust tube. Results confirmed that the thermal choking of the flow inside the exhaust tube was responsible for the sudden increase in combustion pressure. Also, high pressure exponent of solid propellants is critical sensitive to the occurrence of thermal choking exhaust pipe. Additionally, numerical simulation showed that the sudden increase in combustion pressure was less possible in diverging pipe because thermal choking is more reluctant to occur.

• Journal of the Korean Society of Safety
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• v.7 no.3
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• pp.108-116
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• 1992

가스누설에 의한 화재는 폭발을 동반하는 경우가 많을 뿐만아니라 연소가 급격하게 이루어지고, 피해 또한 크기 때문에 이를 미연에 방지하기 위하여 지하가등 일정규모 이상의 특정방화 대상물에서 가스연소기를 사용할 경우에는 가스누설 화재경보설비의 설치를 의무화하고 있다.(중략)

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.9
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• pp.1744-1759
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• 1992

A multidimensional simulation of turbulent flow and combustion with swirl in the cylinder of SI engine is implemented to clarify the effects of swirl. present simulation employs the ICED-ALE numerical technique, the skew-upwind difference scheme, a modified k_.epsilon. turbulence model, a combustion model of Arrhenius type and turbulence-mixing-control type. First, the calculations for swirling flow in an axisymmetric cylinder are carried out. The results are compared with the experimental data to validate the numerical analysis. Second, the calculations for intake, compression and combustion processes in an axisymmetric cylinder are performed. The effects of swirl on turbulent flow and combustion are examined through the parametric study of swirl number 0.0, 0.6, 1.2 and 2.4. As a result, it is numerically shown that the turbulent kinetic energy and the swirl velocity, which are produced during the intake process, affect the combustion process.

• Fire Science and Engineering
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• v.13 no.3
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• pp.27-33
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• 1999

Water mist fire suppression experiment is carried out for a personal computer fire. F Fire spread is observed and analyzed by measured temperatures without the injection of t the water mist. The extinguishment test shows that oxygen concentration increases r rapidly upon the water mist injection. Also $C0_2$ concentration decreases steeply due to t the injection because the water mist suppresses combustion reaction. Relative humidity g goes up very steeply by the injection.

• Applied Chemistry for Engineering
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• v.23 no.3
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• pp.333-338
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• 2012

To verify the utilization of fluff refuse derived fuel (RDF) as energy source, the combustion charateristic has been studied by an experimental combustion furnace under various temperatures. The characteristics of flue gas, dust and residue from fluff RDF combustion has been analyzed and compared with those of pelletized RDF. From this work, it was found that the incomplete combustion of fluff RDF was greater than that of pelletized RDF because the combustion reaction rate of fluff RDF was faster than that of pelletized RDF, and oxgen concentration in fluff RDF combustion decreased rapidly. It was also found that carbon monoxide concentration of flue gas from fluff RDF combustion increased with combustion temperature because the oxygen consumption and the incomplete combustion increased. Therefore, it is felt that the combustion operation conditions of fluff RDF should be carefully determined.