초임계 탄화수소 항공유의 흡열분해 화학반응 모델 개발을 위한 실험적 연구 = Experimental Study for Development of Endothermic Pyrolysis Reaction Model of Supercritical Hydrocarbon Aviation Fuel

다국어 초록 (Multilingual Abstract)

Active regenerative cooling is a key technology for mitigating the severe thermal loads of hypersonic vehicles by utilizing hydrocarbon aviation fuel as a coolant. In the regenerative cooling system, the fuel flows through the cooling channels and is heated to a supercritical state, absorbing a large amount of heat and undergoing endothermic decomposition. The fuel decomposed in this way significantly impacts both the cooling characteristics of the hypersonic vehicle and the combustion performance of the scramjet engine. Therefore, it is essential to quantitatively characterize the supercritical pyrolysis behavior of hydrocarbon aviation fuels and to develop a pyrolysis reaction model that can be directly used for regenerative cooling analysis. In this study, a batch-reactor-based supercritical pyrolysis experimental system with standardized operating procedures and quantitative gas and liquid product analysis using gas chromatography, and a CFD-applicable global reaction model for a representative hydrocarbon aviation fuel was developed.
Using the developed system, pyrolysis experiments were performed for exo-THDCPD, n-dodecane, and military jet fuel JP-8 under supercritical conditions. Wide ranges of fuel conversion and gas production rate were obtained under varying temperatures, residence times, and initial pressures. Gaseous products consisted mainly of H₂ and C1–C5 hydrocarbons, while liquid products exhibited high compositional complexity and were classified according to parent molecular structure. Product distributions were systematically evaluated as a function of fuel conversion to identify thermal decomposition trends.
Based on these experimental data, a CFD-applicable global reaction model for JP-8 was developed and validated. GC–MS analysis yielded an average JP-8 chemical formula of C11.04H21.70, which was used to formulate a surrogate mixture. To reduce chemical complexity for numerical implementation, heavy products were represented using lumped species such as C5, CC5, and CnH2n−6. A one-step global pyrolysis model was constructed for the primary cracking regime up to 30% fuel conversion, and secondary cracking reactions for C5 and CC5 were incorporated to extend the model to higher conversions. The final model reproduced experimental product distributions in CFD simulations of a regenerative cooling channel, with most predictions within ±25% of measured values.
These results provide insight into supercritical pyrolysis of hydrocarbon aviation fuels and demonstrate the model’s applicability for predicting fuel flow and decomposition behavior in regenerative-cooled channels, supporting the design and analysis of regenerative cooling systems for hypersonic vehicles.

목차 (Table of Contents)

• Ⅰ. 서론 1
• 1.1 연구 배경 1
• 1.2 연구 현황 3
• 1.3 연구 목적 6
• Ⅱ. 실험 시스템 및 분석 방법 8
• 2.1 열분해 반응 실험 시스템 8
• 2.2 회분식 반응기 설계 및 개선 10
• 2.3 열분해 실험 절차 13
• 2.4 열분해 생성물 분석 15
• 2.4.1 가스 크로마토그래피(GC) 시스템 구성 15
• 2.4.2 열분해 지표 산정법 19
• 2.4.3 수소 생성량 정량 분석법 23
• 2.5 실험 불확도 분석 29
• Ⅲ. 연료별 열분해 실험 결과 32
• 3.1 exo-THDCPD의 열분해 특성 실험 33
• 3.1.1 연료 특성 및 실험 조건 33
• 3.1.2 연료 전환율 및 기체 생성률 36
• 3.1.3 열분해 생성물 분포 특성 39
• 3.2 n-dodecane의 열분해 특성 실험 43
• 3.2.1 연료 특성 및 실험 조건 43
• 3.2.2 열분해 실험 시스템 검증 45
• 3.2.3 연료 전환율 및 기체 생성률 49
• 3.2.4 열분해 생성물 분포 특성 51
• 3.3 JP-8의 열분해 특성 실험 55
• 3.3.1 연료 특성 및 실험 조건 55
• 3.3.2 연료 전환율 및 기체 생성률 57
• 3.3.3 열분해 생성물 분포 특성 61
• Ⅳ. 열분해 모델 개발 및 수치해석 65
• 4.1 JP-8 surrogate 구성 65
• 4.2 JP-8 열분해 모델 개발 68
• 4.2.1 생성물 selectivity 및 분포 특성 분석 68
• 4.2.2 1차 분해 반응 모델 개발 72
• 4.2.3 2차 분해 반응 모델 개발 77
• 4.3 열분해 모델을 적용한 수치해석 79
• 4.3.1 해석 형상 및 격자 생성 79
• 4.3.2 경계 조건 및 해석 설정 80
• 4.3.3 수치해석 결과 분석 83
• Ⅴ. 결 론 89