• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집B
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• pp.155-160
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• 2001

The low NOx characteristics have been investigated to develop the combustor for micro turbine. The lean premixed combustion technology was applied to reduce the NOx emission. The test was conducted at the condition of high temperature and ambient pressure. The combustion air which has the temperature of $450\sim650K$ were supplied to the combustor through the air preheater. The temperature and emissions of NOx and CO were measured at the exit of combustor, The exit temperature and NOx were increased and CO was decreased with increasing inlet air temperature. The premixing chamber can be operated very lean condition of equivalence ratio around 0.35. The NOx was decreased with decreasing the equivalence ratio. The CO was decreased with decreasing the equivalence ratio, but the CO was increased with decreasing the equivalence ratio below 0.4. But, at the very lean condition of equivalence ratio below 0.35 both NOx and CO were increased because of the flame unstability. The NOx was decreased and CO was increased with increasing inlet air flowrate. This results can be used to determine the size of combustor. Consequently the performance of combustor shows the possibility of the application to the gas turbine system.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.83-88
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• 2003

The concept of lean-premixed combustion in gas turbine combustor operation has become a standard in recent years as an effective means to meet stringent environmental standards on NOx emissions. Various types of air-fuel premixer, which affect greatly NOx emission and stability of lean-premixed low NOx combustor, were investigated experimentally to reduce the NOx emission. One type of the premixers is selected by experiments and applied it to 70kW class lean-premixed gas turbine combustor. The exit temperature and emissions of CO and NOx were measured with equivalence ratios at ambient pressure. From the results, the emissions of CO and NOx were influenced by the type of air-fuel premixer. As the mixing length of air and fuel is longer, the NOx and CO emission were decreased in the primary reaction zone. Compared with of conventional combustor, the lean-premixed low NOx combustor has low NOx emission characteristics.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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• pp.305-308
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• 2005

본 논문은 30ton급 액체로켓엔진 연소기의 연소시험 검증용 제작에 관한 것이다. 기본설계와 상세설계를 통해 도면을 작성하고, 이에 따라 제작하였다. 연소기는 크게 헤드부와 챔버부로 구성되며, 챔버는 KSR-III에 적용되었던 내열재 챔버와 재생 냉각 방식의 챔버를 제작하였다. 연소기 헤드는 저온 특성이 좋은 SUS316L 재료를 사용하였다. 내열재 챔버는 내부는 silica/phenolic 재료를 사용하였고, 외부케이스는 SUS316L을 적용하였고, 재생 냉각 챔버는 C18200과 SUS316L 재료를 사용하였다. 선반 가공, 일반 밀링 가공, MCT 가공등의 기계적 가공을 한 후 전해 연마를 통해 이물질을 제거 하였다. 분사기와 분사기 플레이트의 접합과 재생 냉각 챔버 등 일부 부품의 접합은 구조적인 특성으로 인해 브레이징 기법을 적용하였다.

• 한국대기환경학회지
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• 제12권2호
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• pp.131-139
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• 1996

The developent of ceramic combustor is being increased beca- use of the excellent physical properties of ceramic material, that is, high-resistant strength, high emissivity power and high corrosin-resistance. Ceramic combustor has been interested in the application of ultra-lean combustion for low NO$_{x}$ emission and gaseuos waste incineration with good combustion. This experimental study was conducted to investigate the combustion and emission characteristics of wall recess type ceramic combustor with equivalence ratio, mixture flow velocity and wall recess depth as parameters. The results in this study are as follows: 1. Wall recess played a important role to extend flame stability region. 2. The peak temperature of gas was peoportional to equivalence ratio, mixture flow velocity and wall recess depth. 3. The static pressure of mixing chamber and inlet temperature depended on the position of flame zone. 4. NO reduction was achieved by lean mixture without lower combustibility.y.

• 한국연소학회:학술대회논문집
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• 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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• pp.139-143
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• 2003

Study on the ignition characteristics of combustor and gas generator for LOx-kerosene liquid rocket engine was performed experimentally through a series of combustion tests of sub-scale engine combustor and gas generator. Characteristic of gas-torch ignitor based on gaseous methane and gaseous oxygen was compared with hypergolic ignition using propellant tri-ethyl-aluminium. Gas-torch ignitor showed good performance on igniting sub-scale liquid rocket engine combustor and gas generator. It was observed that the ignition delay is also affected by the extent of nitrogen in the combustion chamber.

• Advances in aircraft and spacecraft science
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• 제7권3호
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• pp.187-202
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• 2020

The exhaust nozzle serves back pressure of Pulse detonation combustor, so combustion chamber gets sufficient pressure for propulsion. In this context recent researches are focused on influence of nozzle effect on single cycle detonation wave propagation and propulsion performance of PDE. The effects of various nozzles like convergent-divergent nozzle, convergent nozzle, divergent nozzle and without nozzle at exit section of detonation tubes were computationally investigated to seek the desired propulsion performance. Further the effect of divergent nozzle length and half angle on detonation wave structure was analyzed. The simulations have been done using Ansys 14 Fluent platform. The LES turbulence model was used to simulate the combustion wave reacting flows in combustor with standard wall function. From these numerical simulations among four acquaint nozzles the highest thrust augmentation could be attained in divergent nozzle geometry and detonation wave propagation velocity eventually reaches to 1830 m/s, which is near about C-J velocity. Smaller the divergent nozzle half angle has a significant effect on faster detonation wave propagation.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2005년도 제24회 춘계학술대회논문집
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• pp.299-304
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• 2005

본 논문에서는 연소실 압력 53bara, 추진제 유량 90kg/s, 연소효율 $94\%$, 지상 비추력 253sec을 갖는 액체로켓엔진 실물형 연소기의 설계 전반에 대해 기술하였다. 연소기의 성능에 미치는 연소가스의 물성치, 특성속도, 추력계수 그리고 비추력에 대해 알아보았고, 연소기의 기하학적인 형상에 대해서도 기술하였다. 연소기는 분사기를 장착한 연소기 헤드, 재생냉각 채널을 가지고 있는 연소실로 구성되어 있다. 지상연소시험을 위해 제작한 내열재 삭마 방식의 연소실, SUS 배플을 장착하고 실린더부와 노즐부가 분리된 연소기, 배플 분사기를 장착하고 제생냉각부가 일체형인 연소기에 대해 기술하였다.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2006년도 제33회 KOSCO SYMPOSIUM 논문집
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• pp.235-241
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• 2006

Catalytic combustion is one of the suitable methods for micro power source due to high energy density and no flame quenching. Catalyst loading in the micro structured combustion chamber is one of the most important issues in the development of micro catalytic combustors. In this research, to coat catalyst on the chamber wall, two methods were investigated. First, $Al_2O_3$ was selected as a support of Pt and $Pt/Al_2O_3$ was synthesized through the alumina sol-gel procedure. To improve the coating thickness and adhesion between catalyst and substrate, heat resistant and water solvable organic-inorganic hybrid binder was used. Porous silicon was also investigated as a catalyst support for platinum. Through the parametric studies of current density and etching time, fabrication process of $1{\sim}2{\mu}m$ of diameter and about $25{\mu}m$ depth pores was confirmed. Coated substrates were test in the micro channel combustor which was fabricated by the wet etching and machining of SUS 304. Using $Pt/Al_2O_3$ coated substrate and Pt coated porous silicon substrate, conversion rate of fuel was over 95% for $H_2$/Air premixed gas.

• 대한기계학회논문집B
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• 제26권10호
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• pp.1387-1393
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• 2002

The measurement of velocity and stain rate field has been conducted in opposed impinging jet combustion. When a smaller diameter (5mm) orifice of pre-chamber was used, previous studies had reported that the combustion phase showed a shift from weak turbulent combustion to moderate turbulent combustion in the modified Borghi Diagram. In the case with smaller orifice diameter (5mm), NOx emission was substantially reduced by a factor 1/2 while the combustion pressure remains at the same as that in the conventional combustion. Hence, in this study, the experiment setup using PIV technique was designed to identify the relation of the strain rate distribution and NOx reduction associated with moderate turbulent combustion. As a result, it was found that the highly strained pockets are widely distributed during the combustion in the middle of chamber when the orifice diameter is 5mm. And the corresponding PDF distribution of strain rates she was the smoothly distributed strain .ate within the range of ｜$\pm$1000｜ (1/sec) rather than a spike shape about zero point. This is the unique feature observed in the combustion with 5mm orifice diameter. Therefore, it can be concluded that the substantial NOx reduction in opposed impinging combustor is mainly attributed to the strain rate distribution within the range of ｜$\pm$1000｜resulting in the combustion phase shift to moderate turbulent combustion.

• 한국추진공학회지
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• 제11권5호
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• pp.31-36
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• 2007

연소 압력이 70 bar인 고압 축소형 연소기의 연소성능 특성을 알아보았다. 모든 연소시험은 하드웨어의 손상 없이 성공적으로 이루어졌다. 분사기의 혼합특성과 분사기 배열이 연소성능에 큰 영향을 미치는 요소임을 파악하였다. 연소기의 특성속도는 외부 혼합보다 내부 혼합 분사기에서 더 크게 나타났으며 단위분사기당 추진제의 유량이 감소함에 따라 특성속도도 증가하였다. 추진제 매니폴드 및 연소실에서 측정된 압력 섭동은 평균 연소압력의 3% 이하로 연소안정성 기준치 보다 낮은 값을 보여 안정적인 연소기임을 보였다.