• Title/Summary/Keyword: 라디칼 자발광강도

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OH-and CH-Radical Chemiluminescence Characteristics in the Spray Combustion of Ultransonically Atomized Kerosene (초음파에 의해 무화된 케로신 분무연소에서의 OH 라디칼 및 CH 라디칼 자발광 특성)

  • Kim, Min Cheol;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.1
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    • pp.72-79
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    • 2018
  • An experimental study was performed to investigate the chemiluminescence characteristics in the spray combustion of ultransonically atomized kerosene. The radical intensity of the spray flame was measured using an ICCD camera and the amount of fuel consumed was obtained by a precise flow-rate measurement technique during combustion. Fuel consumption increased linearly with the increase in carrier-gas flow rate, and typical group combustion, which is a characteristic of spray combustion, was observed. It was found from the analysis of chemiluminescence that the maximum emission intensities of OH and CH radicals decrease, and they move downstream resulting in the increase in a vivid reaction zone as the spray flow rate increases.

Symptoms on Generation of Combustion Oscillation and their Detection (진동연소 발생에 관한 징후와 이의 검출)

  • 양영준
    • Journal of Energy Engineering
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    • v.13 no.3
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    • pp.205-213
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    • 2004
  • Usefulness of an optical fiber was demonstrated by detecting the generation of self-excited combustion oscillations. OH chemiluminescence intensity detected by the optical fiber showed mostly excellent agreement with those obtained by high speed CCD camera measurements when combustion oscillations were strong. Symptoms of self-excited combustion oscillation were also studied in order to predict the onset of combustion oscillation before it proceeded to a catastrophic failure. For the purpose, we have found and proposed unique measures to tell the onset of self-excited combustion oscillations based on the careful statistics of fluctuating properties in flames, such as pressure or omission of OH radicals.

Effects of the Recess and Propellants Mass Flow on the Flammability Limit and Structure of Methane-Oxygen Diffusion Flame (인젝터 리세스와 추진제 공급유량이 메탄-산소 확산화염의 가연한계와 구조에 미치는 영향)

  • Hong, Joon Yeol;Bae, Seong Hun;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.22 no.1
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    • pp.28-35
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    • 2018
  • In order to analyze the flammability limit and structure of the gaseous methane-gaseous oxygen diffusion flame formed through a shear coaxial injector, combustion experiments were carried out according to the condition of injector recess and propellant mass-flow rate. As a result, it was confirmed that stable anchored flame was observed even at the high oxygen Reynolds number as the propellant momentum flux ratio increased, and that the recess had no significant influence on the flame shape and flammability limit. The anchored flame visualized through a chemiluminescence showed the maximum OH radical emission intensity at a specific position, irrespective of the propellant injection condition, and the radical intensity was greatly reduced by the injector recess.

Combustion Characteristics of Model Gas Turbine Combustor -Radical Luminous Intensity and Local Equivalence Ratio Measurement- (모형 가스터빈 연소기의 연소특성 -라디칼 자발광강도와 국소당량비계측에 대하여-)

  • 최병륜;김태한
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.4
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    • pp.1064-1071
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    • 1994
  • There are three active radicals which become to the scale of flame diagnostics at the flame front. They are OH, CH and $C_2$ radical. For this, optical measurement system which could monitor simultaneously the luminous waves of three radicals, was constructed. These were analyzed statistically into the cross correlation, coherence and phase. Through such an statistical treatment, combustion characteristics was investigated at the primary zone of gas turbine combustor. The local equivalence ratio was predicted with the ratio of luminuous intensity between CH and $C_2$ radical. This result was matched up to the equivalence ratio calculated from gas composition within 5% error. In general, equivalence ratio was said to be 1.0 at flame front, but it could be increased up to about 1.2 depending on the degree of swirl intensity in case of changing properly the air amount of primary zone.

Effects of Swirl/Shear-coaxial Injector on the Dynamic Behavior of Gaseous Methane-Gaseous Oxygen Diffusion Flame (스월/전단 동축형 인젝터가 기체메탄-기체산소 확산화염의 동역학적 거동에 미치는 영향)

  • Hong, Joon Yeol;Bae, Dae Seok;Kim, Jeong Soo
    • Journal of the Korean Society of Propulsion Engineers
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    • v.23 no.1
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    • pp.1-8
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    • 2019
  • To analyze the dynamic behavior and the structure of the gaseous methane-gaseous oxygen diffusion flame formed by a swirl/shear-coaxial injector, combustion experiments were carried out under different propellant injection conditions. As a result, the OH radical emission intensity of the diffusion flame visualized through chemiluminescence was observed to increase as the propellant mass flow and the momentum flux ratio increased. And flames with swirl showed a more high radical emission intensity than those without swirl.

An Experimental Study on Flame Structure and Combustion Characteristics of Turbulent Diffusion Flame(II) (난류확산화염의 화염구조와 연소특성에 관한 실험적 연구(2))

  • Choe, Byeong-Ryun;Jang, In-Gap;Choe, Gyeong-Min
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.3
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    • pp.1050-1060
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    • 1996
  • Recently, attention has been paid to the flame diagnostic by noncontact methods which dose not deform the flame shape. One of them is a method which is using the radical luminous intensity. Generally, this diagnostic method using radical luminous has been investigated its reliability by applying to laminar flame. This study, however, investigated each radical luminous signals through stocastical analysis like auto-correlation, cross-correlation, phase and coherence which were acquired from measuring radical luminous intensity of OH, CH, $O_{2}$, radicals in turbulent diffusion flame. To compare radical luminous intensity in flame with temperature, ion current and concentration , radious distribution of each properties was investigated and considered. In radical luminous intensity, correlation in the reaction zone of flame was higher than in correlation in combusted gas zone. And radious distribution of radical luminous intensity was corresponded with radious distribution of temperature, ion current and concentration. The result of the study confirms that a radical luminous flame diagnosis is possible in the turbulent diffusion flame.

An Experimental Study on Flame Structure and Combustion Characteristics of Turbulent Diffusion Flame(III) (난류확산화염의 화염구조와 연소특성에 관한 실험적 연구)

  • Jang, In-Gap;Choe, Gyeong-Min;Choe, Byeong-Ryun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.20 no.7
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    • pp.2326-2336
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    • 1996
  • So most practical combustor is considered to the swirl flame, it is very important to examinate swirl flame structure and combustion characteristics. Recently, attention has been paid to the flame diagnostic by radical luminous intensity. For swirl flame structure and combustion characteristic, reverse flow boundary, temperature, ion current and radical luminous intensity were measured in the double-coaxial swirl combustor which was used principle of multi-annular combustor. This study had three experimental condition, S-type, C-type, SC-type. S-type and C-type flames were formed recirculation zone, but SC-type flame wasn't formed. C-type flame had two recirculation zone. The position with maximum value of ion current and CH-radical, temperature and OH-radical had similarity distribution almost. Therefore, it is possible that the macro structure of flame was measured by radical luminous intensity in the high intensity of turbulent combustion field which was formed by swirl.