한국연소학회지 · 한국연소학회

Research Article

Comparison of Acquired Signal Stability of Laser-Induced Breakdown Spectroscopy in Combustion Environments using Temporal Laser Pulse Modulation
시간적 레이저 펄스 변조를 이용한 연소 환경에서의 레이저 유도 플라즈마 분광법의 취득 신호 안정성 비교

Yehwan An, Hyungrok Do
안예환, 도형록

Temporal nanosecond laser pulse modulation based on inverse-Bremsstrahlung (IB) absorption was applied to laser-induced breakdown spectroscopy (LIBS) in methane-air combustion environments. A … + READ MORE

Temporal nanosecond laser pulse modulation based on inverse-Bremsstrahlung (IB) absorption was applied to laser-induced breakdown spectroscopy (LIBS) in methane-air combustion environments. A variable pressure chamber (VPC) was used to generate plasma that absorbed the trailing edge of the laser pulse and reduced the pulse width. Argon, air, and nitrogen were tested as modulation gases, and argon showed the strongest modulation effect. Under the argon condition, the transmitted laser energy decreased from 180.6 mJ to 12.01 mJ, while the full width at half maximum (FWHM) decreased from 6.57 ns to 0.969 ns as the VPC pressure increased. LIBS signals obtained with modulated and non-modulated pulses were compared under matched incident laser energy conditions in methane-air flames at 1, 5, and 10 barA. At 10 barA and 35.19 mJ, the non-modulated pulse failed to generate valid optical breakdown, whereas the modulated pulse produced analyzable LIBS signals. These results demonstrate that temporal laser pulse modulation can improve LIBS signal acquisition under high-pressure and low-energy combustion conditions. - COLLAPSE

PDF XML

References Information

30 September 2026
Research Article

Development and Validation of a General Framework for Automated Chemical Reactor Network Generation Based on CFD Simulation Results
CFD 시뮬레이션 결과 기반 자동 화학 반응기 네트워크 생성을 위한 범용 프레임워크의 개발 및 검증

Donghwi Kim, Namsu Kim, Youngtae Guahk, Seongkyun Im
김동휘, 김남수, 곽영태, 임성균

This study presents a framework for the automated generation of chemical reactor networks (CRNs) based on computational fluid dynamics (CFD) simulation results, … + READ MORE

This study presents a framework for the automated generation of chemical reactor networks (CRNs) based on computational fluid dynamics (CFD) simulation results, eliminating the need for complex parameter configurations. In the proposed framework, CFD solutions serve as the primary input for zone partitioning and CRN construction, with inter-zonal mass flow rates determined by computing the mass flux across each computational zone boundary. The framework was validated against the well-established Sandia Flame D benchmark, and the CRN predictions were compared with available experimental data. Furthermore, the statistical convergence of the k-means clustering algorithm was verified to account for its inherent randomness. K=30 was selected as the optimal value, balancing computational cost and accuracy. In the optimal case, the CRN enabled the prediction of emission characteristics using detailed reaction mechanisms at a significantly lower computational cost than CFD. In addition, the framework demonstrated satisfactory qualitative agreement in predicting the distribution of major thermochemical state quantities. Therefore, this framework is expected to serve as a valuable tool for predicting the distribution of thermochemical state variables and for analyzing sensitivity to various chemical reaction mechanisms. - COLLAPSE

PDF XML

References Information

30 September 2026
Research Article

GPR-MOGA-Based Optimization of Combustor Operating Conditions for Enhancing Combustion Efficiency and Reducing NOx Emissions
연소효율 향상 및 NOx 배출 저감을 위한 GPR-MOGA 기반 연소기 운전 조건 최적화

Juwon Kim, Deukgyun Lim, Minha Hwang, Jongkwang Lee, Gil-Eon Jeong, Minwoo W. Lee
김주원, 임득균, 황민하, 이종광, 정길언, 이민우

This study presents a computational fluid dynamics (CFD)-based surrogate optimization framework to determine the optimal operating conditions of a non-premixed bluff-body combustor. … + READ MORE

This study presents a computational fluid dynamics (CFD)-based surrogate optimization framework to determine the optimal operating conditions of a non-premixed bluff-body combustor. The inlet mass flow rates of fuel and oxidizer, along with the fuel inlet temperature, are selected as design variables, while the CH₄ conversion-based combustion efficiency and NO emission index serve as performance metrics. To construct the surrogate model, a database generated via Latin hypercube sampling is utilized to train Gaussian process regression (GPR) models, which are subsequently validated using independent test cases. The trained GPR models demonstrate robust predictive performance, yielding high coefficients of determination for both metrics. By coupling the validated GPR models with a multi-objective genetic algorithm (MOGA), optimal operating conditions are identified to simultaneously maximize combustion efficiency and minimize NO emissions. CFD re-analysis of the optimized operating points confirms significant improvements in combustion efficiency and substantial reductions in the NO emission index compared to the initial trial results. These findings demonstrate that the GPR-MOGA optimization framework employed in this study can efficiently identify optimal operating conditions for enhancing combustion performance and reducing emissions in practical combustors. - COLLAPSE

PDF XML

References Information

30 September 2026
Research Article

100% H₂-Air Flame Behaviors in Coaxial Dual-swirl Injector
동축 이중선회 인젝터에서 100% 수소-공기 화염거동 분석

Junpyo Hong, Hyunchang Lee, Keeman Lee
홍준표, 이현창, 이기만

This study experimentally investigated the effects of swirling direction on the flame structure and lift-off behavior of a pure hydrogen–air flame in … + READ MORE

This study experimentally investigated the effects of swirling direction on the flame structure and lift-off behavior of a pure hydrogen–air flame in a coaxial dual-swirl injector for gas-turbine applications. Hydrogen fuel and combustion air were supplied separately through a central nozzle and an outer annular nozzle, respectively. The thermal input was fixed at 5 kW, while the outer-air velocity was set to 10 and 20 m/s. The reaction-zone distributions and time-averaged velocity fields under co-swirling and counter- swirling conditions were characterized using 10 kHz high-speed OH-planar laser-induced fluorescence (OH-PLIF) and two-dimensional particle image velocimetry (2D-PIV). At an outer-air velocity of 10 m/s, an attached M-shaped flame consisting of outer and inner flames was observed. At 20 m/s, the outer flame detached from the nozzle and transitioned to a V-shaped lifted flame. Under the co-swirling condition, both the central recirculation zone (CRZ) and inner recirculation zone (IRZ) were formed, whereas only the CRZ was clearly identified under the counter-swirling condition. Under the lifted-flame condition, the CRZ extended upstream toward the nozzle tip for both swirling configurations. The increased outer-air velocity enhanced the axial momentum of the outer swirling flow and intensified the velocity gradients near the recirculation-zone boundary, while promoting the radial redistribution of the central hydrogen jet. These near-nozzle flow modifications were considered to increase the local velocity and aerodynamic strain near the inner-nozzle lip, thereby weakening flame stabilization and promoting flame lift-off. - COLLAPSE

PDF XML

References Information

30 September 2026
Research Article

Estimation of Flame Temperature Using the Background-Oriented Schlieren Technique (BOS)
배경 지향형 슐리렌 기법(BOS)을 이용한 화염 온도 추정

Muhammad Nouman Rafiq, Seojeong Park, Hyemin Kim
무하마드 노우만라피크, 박서정, 김혜민

This study applied background-oriented schlieren (BOS) to reconstruct radial temperature distributions of a premixed propane-air flame at equivalence ratios of 0.9, 1.0, … + READ MORE

This study applied background-oriented schlieren (BOS) to reconstruct radial temperature distributions of a premixed propane-air flame at equivalence ratios of 0.9, 1.0, and 1.1. Background-image displacements were obtained using PIVlab and converted into temperature through deflection-angle calculations, Abel inversion, the Gladstone-Dale relation, and the ideal gas law. The reconstructed fields revealed a clear dependence on flame condition: the stoichiometric flame exhibited the strongest and widest high- temperature region, the lean flame showed a reduced thermal intensity, and the rich flame displayed a more localized hot core near the centerline. Radial temperature profiles at y = 30 mm were validated against corrected thermocouple measurements. BOS captured the overall radial decay from the flame core to ambient conditions. Quantitatively, the stoichiometric and rich flames showed better agreement, with mean absolute error (MAE) and root mean square error (RMSE) values of 33.19 and 44.28 K and 35.86 and 38.75 K, respectively, while the lean flame exhibited larger errors of 70.08 and 91.67 K. These deviations occurred mainly near the central axis and may be linked to weaker refractive-index gradients and inversion sensitivity. Sequential reconstruction over 0.5 s indicated that the temperature-field structures were generally maintained, thereby demonstrating the potential of BOS for non-intrusive flame-temperature estimation. However, improved centerline validation and further uncertainty quantification are still required. - COLLAPSE

PDF XML

References Information

30 September 2026
Research Article

A Study of Combustion Dynamic Characteristics in a H2/CH4 Gas Turbine Combustor with Nozzle Center Airflow
수소 혼소 가스터빈 연소기의 노즐 중심 공기 유동에 따른 연소 동특성 연구

Hyung Chul Kim, Jaehong Choi, Youngbin Yoon
김형철, 최재홍, 윤영빈

The unique combustion characteristics of hydrogen, which are distinct from those of conventional methane fuel, can cause non-periodic combustion dynamics issues and … + READ MORE

The unique combustion characteristics of hydrogen, which are distinct from those of conventional methane fuel, can cause non-periodic combustion dynamics issues and thermo-acoustic combustion instability in an H2/CH4 premixed gas turbine combustor. Experiments were conducted to comparatively analyze two different nozzle configurations: the Open and Closed nozzles, where the Open nozzle has a center air channel. The stability map was identified over the operational equivalence ratio range, including the flashback and lean blow-off (LBO) limits, to analyze the effect of the center air channel. The results showed that the dominant frequency of combustion instability was independent of the nozzle configuration. However, chemiluminescence imaging revealed that the center air channel modified the flame structure, resulting in a noticeable reduction in the amplitude of combustion instability for the open nozzle. These results indicate that differences in nozzle configuration affect the combustion dynamics and can be modified to be suitable for hydrogen combustion in a gas turbine. - COLLAPSE

PDF XML

References Information

30 September 2026

리스트형 보기 썸네일형 보기

Journal Informaiton

Journal of the Korean Society of Combustion

Journal of the Korean Society of Combustion

Online submission

Journal Informaiton Journal Informaiton - close