• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.3
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• pp.204-211
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• 2019

The analysis on two-phase flow in a Lean Direct Injection(LDI) combustor has been investigated. Linearized Instability Sheet Atomization(LISA) and Aerodynamically Progressed Taylor Analogy Breakup(APTAB) breakup models are applied to simulate the droplet breakup process in hollow-cone spray. Breakup model is validated by comparing penetration length and Sauter Mean Diameter(SMD) of the experiment and simulation. In the LDI combustor, Precessing Vortex Core(PVC) is developed by swirling flow and most droplets are atomized along the PVC. It has been confirmed that all droplets have Stokes number less than 1.0.

• Journal of the Korean Society of Propulsion Engineers
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• v.18 no.2
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• pp.1-9
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• 2014

To investigate the flame dynamics in an annular combustor with single swirl injector, a 3D large-eddy simulation (LES) and a level-set flamelet turbulent combustion model have been implemented. The LM6000 developed by GEAE has been used as the combustor of concern and boundary conditions are based on experimental data. The strong central toroidal recirculation zone induced by the volume expansion of the combustion gas and the vortex breakdown continuously occurred through the procession of the vortex with decreasing strength, are observed.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.120-127
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• 2017

High temperature oxygen and water vapor was generated from catalytic decomposition of rocket grade highly concentrated hydrogen peroxide, and monopropellant thruster system was developed and applied into space propulsion system. In this research, background research and conceptual design of underwater propulsion system using catalytic decomposition of hydrogen peroxide was progressed. Two types of system was designed with different steam injection methods. Propulsion system that has ring-type steam injector was manufactured and performance estimation of system was performed with different nozzle exit area. Performance evaluation with central steam injection type jet engine will be progressed in the future.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.10
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• pp.60-65
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• 2003

An experimental study was performed to understand ignition characteristics of gas turbine combustor with rotating fuel injection system. Liquid fuel applied to the inner surface of rotating fuel nozzle which was driven by high speed electrical motor is flung away by centrifugal forces. The real scale combustor and test rig was manufactured and tested under atmospheric condition in KARl combustion test facility. From the test results, this combustor ignition characteristics are highly dependent upon fuel nozzle rotating speed. Futhermore, combustor exit gas temperature was rapidly changed by increasing or decreasing the fuel nozzle rotating speed.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.4
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• pp.83-93
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• 2001

A swirler with turbulence generator is designed and manufactured for generating many small-scale eddies in the combustor which contribute to enhancing mixing effect between fuel and air. The method results in not only the disadvantage of pressure loss but also the advantage of promoting combustion and reducing NOx. For the purpose of the study, four kinds of swirler with different turbulence generator area (0%, 3%, 7%, and 12% of reducing flow area) are designed to confirm the effect of mixing according the variation in the area of the turbulence generator. The mixing of combustor in the radial direction is significantly improved and the distributions of flames and temperature are well distributed throughout the cross section of a combustor as area of swirl generator is increased.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.1
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• pp.78-84
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• 2005

In the chemical laser system with a radial expansion nozzle array, the laser beam generation is achieved by mixing F atom from supersonic nozzle and $D_{2}$ molecule from holes of round-bended supply line. Based on that the fuel injection angle with main stream has a great influence of performance on supersonic combustor, the effects of $D_{2}$ injection angles with the main F flow on mixing enhancement are numerically investigated. The results are discussed by comparison with three cases of $D_{2}$ injection angles; $10^{o}$, $20^{o}$ and $40^{o}$ with the main flow direction. Major results reveal that as the $D_{2}$ injection angle increases, the maximum small signal gains and the static pressure in the laser cavity become higher. Consequently, the $D_{2}$ injection angle between $20^{o}$ and $40^{o}$ is recommended as an optimized geometric parameter in consideration of both of high gains and low cavity pressure.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.68-74
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• 2006

An experimental study was carried out to investigate the combustion characteristics of the slinger combustor. A combustion test rig was manufactured and installed in KARI combustor test facility. From the ignition test results, we found that there were two major factors influencing the ignition limits; by increasing the rotational speed and the air mass flow rate, a better ignition performance was attained. From the combustion test results, we obtained 99.6% combustion efficiency, 15% pattern factor, and 3% profile factor. The results in this work indicate that the ignition and combustion characteristics of a slinger combustor are markedly different from those of a conventional annular combustor.

• 한국신재생에너지학회:학술대회논문집
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• 2008.10a
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• pp.250-253
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• 2008

최근 석탄 가스화 기술은 화석연료인 석탄을 기존의 공해물질 발생을 90%이상 줄이면서 고효율로 활용할 수 있는 방법으로 각광받고 있다. 본 연구는 당 센터에서 보유하고 있는 습식 석탄 가스화기의 성능 향상을 위하여 버너의 형태에 따른 미립화 특성을 파악하였으며, 가스화기의 버너로 적용하여 가스화 특성 실험을 실시하였다. 미립화 특성을 파악하기 위하여 개발되어진 3가지 형태의 버너를 Cold Test장치를 이용하여 $O_2$/Fuel Ratio 및 버너의 내부 혼합 방식, 분사각도에 따른 미립화 특성을 관찰하였으며, 입도 분석은 심파텍사의 입도 분석기를 이용하여 측정하였다. 실험 결과 이중혼합식 버너가 미립화 특성이 가장 우수하게 나타났으며, 외부혼합식 버너와 환형 버너의 경우 비슷한 미립화 특성을 나타내었다. 가스화기에 적용하여 실험한 결과 미립화 특성이 우수하게 나타나는 경우 가스화 특성 또한 우수하게 나타남을 확인하였다.