표제지
목차
Nomenclature 6
초록 8
제I장 서론 9
1.1. 연구의 필요성 9
1.2. 연구목적 및 내용 12
제II장 이론적 고찰 20
2.1. 대향류 확산화염 20
2.2. S-curve 거동 특성 22
제III장 실험장치 및 방법 26
3.1. 실험장치 27
3.1.1. 대향류버너 27
3.1.2. 상부버너 냉각수 순환장치와 하부버너의 장막유동 29
3.1.3. 질량유량 제어기 30
3.2. 실험방법 31
3.2.1. 대향류 화염의 소화특성 가시화 31
3.2.2. 화염분석을 위한 Matlab 기법 32
3.2.3. 실험 조건 33
제IV장 실험결과 및 고찰 36
4.1. 장막유동 유량 변화에 따른 효과 36
4.1.1. 결과 및 논의 36
4.1.2. 결론 49
4.2. 버너직경 변화에 따른 효과 51
4.2.1. 결과 및 논의 51
4.2.2. 결론 61
제V장 결론 63
참고문헌 67
Abstract 74
Table 4.1. Divisions of extinction mode 40
Table 4.2. The classification of flame extinction modes for the burner diameters of 18.0, 26.0, and 46.0 mm 55
Fig. 1.1. Characteristics of triple(or edge) flame in mixing layer 13
Fig. 1.2. Low strain rate counterflow configuration 17
Fig. 2.1. (a) Schematic representation of temperature as a function of Z, (b) S-curve of maximum flame temperature with strain rate or scalar dissipation rate 24
Fig. 2.2. Flame response for an adiabatic diffusion flame system "S-curve" 25
Fig. 3.1. Schematic diagram of counterflow burner and flow systems 26
Fig. 3.2. Experimental apparatus of counterflow burner 28
Fig. 3.3. Nozzle exit velocity with radial distance across burner nozzle for burner diameter 18, 26 and 46mm 28
Fig. 4.1. Variation of critical mole fractions at flame extinction with global strain rate in terms of curtain flowrate at the velocity ratio of (a) 3, (b) 4, (c) 5 38
Fig. 4.2. Variation of critical mole fractions at flame extinction with global strain rate in terms of velocity ratio at the curtain flowrate of (a) 4, (b) 8, (c) 12 l/min 39
Fig. 4.3. Variation of mean flame radius with global strain rate in terms of curtain flowrate at the velocity ration of (a) 3, (b) 4, (c) 5 42
Fig. 4.4. Variation of mean flame radius with global strain rate in terms of velocity ratio at the curtain flowrate of (a) 4 l/min, (b) 8 l/min, (c) 12 l/min 43
Fig. 4.5. (a) Temporal variation of flame disk radius, (b) its temporal variation during the expanding flame period, and (c) that during the shrinking flame period; ag = 15 s-1, Vr = 4, XN₂ = 0.639 and Curtain flow-rate = 8 l/min(이미지확인) 45
Fig. 4.6. Variations of edge travelling speed with flame radius according to curtain flowrate at ag = 15 s-1 and Vr = 4.(이미지확인) 48
Fig. 4.7. Variations of critical mole fractions at flame extinction with global strain rate at various flame conditions 52
Fig. 4.8. Various flame extinction modes for the burner diameters of 18 mm 54
Fig. 4.9. Various of critical flame radius for flame extinction with global strain rate in terms of (a) D = 18 mm, L = 15 mm (b) D = 26 mm, L = 15 mm (c) D = 46 mm, L = 15 mm (d) D = 46 mm, L = 20 mm 59
Fig. 4.10. Normalized critical flame lengths corresponding to individual regime 60
Fig. 4.11. The Characteristic of non-dimensionalized edge flame oscillation 60