Article
Thermodynamics
David M. Peterson
Summary: Simulations were conducted for a round supersonic combustor using a wall-modeled large eddy simulation approach to model turbulence. Combustion was modeled using a small quasi-global mechanism and a more detailed skeletal mechanism. Sensitivity to grid resolution was investigated and a function for the model constant in the partially-stirred reactor model was found. Different combinations of mechanisms and turbulent combustion models can predict the location of the pre-combustion shock train and peak mean pressure, but there are significant differences in temperature and heat release rate fields.
PROCEEDINGS OF THE COMBUSTION INSTITUTE
(2023)
Article
Engineering, Aerospace
Xin Li, Yu Pan, Chaoyang Liu, Xiao Liu
Summary: To avoid the thermal choking problem in scramjet, a wall-expansion scheme is usually adopted, but it poses challenges to flame holding. This paper uses large eddy simulation to study the effect of expansion angle change on the flameout limit in the strut-based supersonic combustor. The numerical results show the establishment of the recirculation zone and the role of reflected shock waves in enhancing combustion.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Aerospace
Yuwei Cheng, Qian Chen, Xiaofei Niu, Shufeng Cai
Summary: This paper investigates the supersonic combustion instability in a strut-based scramjet combustor using large eddy simulation and dynamic mode decomposition. The results show significant pressure oscillation in the combustor under certain conditions, which are related to wake instability, shear layer instability, shear layer and wave interactions, and combustion.
Article
Thermodynamics
Majie Zhao, Zhi X. Chen, Huangwei Zhang, Nedunchezhian Swaminathan
Summary: Large Eddy Simulation with a Perfectly Stirred Reactor model (LES-PSR) is developed to simulate supersonic combustion with high-enthalpy flow conditions. The PSR model considers the viscous heating and compressibility effects on the thermo-chemical state, and is validated through a priori analysis. The model accurately captures shock wave structures, flame characteristics, interactions, and lift-off heights, showing good agreement with experimental data.
COMBUSTION AND FLAME
(2021)
Article
Thermodynamics
Zhiwei Huang, Matthew J. Cleary, Zhuyin Ren, Huangwei Zhang
Summary: The study successfully simulated the multiple features of a supersonic lifted hydrogen jet flame using the MMC-LES approach, accurately predicting flame structure and characteristics. The importance of pressure work and viscous heating in autoignition induction and flame stabilization was highlighted in this research.
COMBUSTION AND FLAME
(2022)
Article
Engineering, Aerospace
Nan Meng, Feng Li
Summary: This study investigated the factors affecting flame fluctuation on unsteady combustion flow fields through large-eddy simulations. The effects of primary and secondary holes in a triple swirler staged combustor on flame propagation and pressure fluctuation in a combustion field were studied. The results revealed a variation in the vortex structure and Kelvin-Helmholtz instability in the combustion field, along with a variation in the pressure pulsation during flame propagation under the influence of the primary and secondary hole structures.
Article
Mechanics
Jian Fang, Xi Deng, Zhi X. Chen
Summary: A Mach 1.5 non-reactive flow in a cavity-stabilized combustor of a model scramjet was studied via direct-numerical simulation, with focus on the interaction among boundary layer, free shear-layer above the cavity and shock wave. Impingement of the free shear-layer on the aft wall of the cavity leads to strong turbulence, high pressure, and compression waves. The analysis reveals that shear production amplifies turbulence in the core of the shear-layer, while deceleration production has a significant impact above the aft wall of the cavity and around the shock interaction points.
Article
Engineering, Aerospace
Chaoyang Liu, Ning Wang, Kai Yang, Dongpeng Jia, Yu Pan
Summary: This study focuses on the stabilization mechanism of a supersonic lifted jet flame in heated coflows, highlighting the competition between autoignition and the propagation of active kernels at the flame base. Using highly-resolved large eddy simulation, it is found that the characteristics of the lifted hydrogen jet combustion gradually vary along the axial direction, with the evolution of turbulent structures and flameholding mechanism being crucial.
Article
Chemistry, Physical
Rocky Simon Pinto, T. Sree Renganathan, S. M. D. Hamid Ansari, T. M. Muruganandam
Summary: Hysteresis in flame stabilization mode transitions in a hydrogen-fueled supersonic combustion test rig was experimentally observed and studied. The effects of equivalence ratio on flame stabilization modes were investigated through measurements of shock system, heat release zones, and flame structure. Three different combustion modes were observed, and the hysteresis phenomena between these modes were analyzed.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Engineering, Aerospace
Fan Li, Guoyan Zhao, Yuhui Huang, Daoning Yang, Guangwei Ma, Yansong Li, Yixin Yang, Peibo Li, Jiajian Zhu, Mingbo Sun
Summary: This study investigates the effect of boundary layer thickness on supersonic combustion in an ethylene-fueled scramjet combustor under Mach 5.5 flight conditions using experiments, numerical simulations, and theoretical modeling. The study finds that while the absolute thickness of the boundary layer increases with a larger combustor, the relative thickness remains thin. The influence of boundary layer thickness on the transverse jet and cavity flow is limited, but the combustion is greatly affected by the combustion chamber scale change. Larger combustion chambers exhibit more violent flames. A theoretical model shows that a large subsonic region leads to a longer fuel residence time and larger Damkohler numbers, indicating the ability of a large combustor to sustain intense combustion. The relative thinness of the boundary layer contributes to intense combustion due to the increased absolute subsonic region filled with combustion products. The study also verifies that the combustion is significantly weakened in a 50 mm shortened isolation section through flame cloud diagrams and quantitative wall pressure data.
AEROSPACE SCIENCE AND TECHNOLOGY
(2023)
Article
Thermodynamics
Achyut Panchal, Suresh Menon
Summary: Understanding combustion and flame stabilization of alternate fuels is crucial for their use in aviation. This study uses large eddy simulation to simulate a real gas turbine combustor and investigate the burning behavior and flame stabilization mechanism of two fuels. The results show that the flame anchor point is premixed, but most heat release comes from fuel pockets burning in a nonpremixed manner.
COMBUSTION AND FLAME
(2022)
Article
Engineering, Aerospace
Pengfei Xiong, Dong Zheng, Yu Tan, Ye Tian, Jialing Le
Summary: This study experimentally investigates the ignition and flame transient development in an ethylene fueled cavity-based supersonic combustor under low conditions. It is found that ethylene can achieve successful ignition and stable combustion at low inflow Mach numbers, with the combustion mode dependent on the global equivalence ratio (ER). Furthermore, the combustion and shockwaves are observed to strengthen each other until a balance is reached, ensuring stable flow structures and combustion.
AEROSPACE SCIENCE AND TECHNOLOGY
(2021)
Article
Mechanics
Prasanth P. Nair, Abhilash Suryan, Vinod Narayanan
Summary: Combustion at supersonic speeds is crucial for improving performance. The research discovers that the divergence angle of the passive strut has an impact on the mixing efficiency and acoustic behavior. Unstable combustion occurs when the divergence angle is too high, while pressure loss decreases with a smaller divergence angle.
Article
Energy & Fuels
Xutao Wei, Meng Zhang, Zhenhua An, Jinhua Wang, Zuohua Huang, Houzhang Tan
Summary: For NH3/air flame, the flame fronts burn to a higher equivalence ratio region, making it prone to extinguishing; the curvature distribution at flame root is mainly dependent on the flame characteristics. Downstream the flows, the curvature distribution is mainly influenced by the flow field characteristics.
Article
Engineering, Multidisciplinary
Jin-cheng Zhang, Ming-bo Sun, Zhen-guo Wang, Hong-bo Wang, Chao-yang Liu
Summary: Flame stabilization is crucial for achieving hypersonic speeds with scramjets, with this study focusing on the autoignition effect in lifted hydrogen jet combustion through large eddy simulations. The results demonstrated the importance of autoignition cascade in flame stabilization, with higher total temperatures reducing lift-off distance but inhibiting autoignition cascade in some cases.
JOURNAL OF ZHEJIANG UNIVERSITY-SCIENCE A
(2021)
Article
Energy & Fuels
Zhiwei Huang, Majie Zhao, Huangwei Zhang
Article
Chemistry, Physical
Zhiwei Huang, Huangwei Zhang
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2020)
Article
Chemistry, Physical
Bing Liu, Jia-chen Xu, Fei Qin, Guo-qiang He, Duo Zhang, Lei Shi
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2020)
Article
Engineering, Aerospace
Lei Shi, Guojun Zhao, Yiyan Yang, Fei Qin, Xianggeng Wei, Guoqiang He
AEROSPACE SCIENCE AND TECHNOLOGY
(2020)
Article
Energy & Fuels
Zhiwei Huang, Huangwei Zhang
Article
Chemistry, Physical
Jian An, Hanyi Wang, Bing Liu, Kai Hong Luo, Fei Qin, Guo Qiang He
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2020)
Article
Engineering, Aerospace
Xianggeng Wei, Tao Bo, Pengbo Wang, Xinjian Ma, Yongchun Lou, Jian Chen
INTERNATIONAL JOURNAL OF AEROSPACE ENGINEERING
(2020)
Article
Chemistry, Physical
Jian An, Guoqiang He, Kaihong Luo, Fei Qin, Bing Liu
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2020)
Article
Mechanics
Zhiwei Huang, Matthew J. Cleary, Huangwei Zhang
Article
Energy & Fuels
Huangwei Zhang, Majie Zhao, Zhiwei Huang
Article
Mechanics
Zhiwei Huang, Huangwei Zhang
Article
Energy & Fuels
Zhiwei Huang, Majie Zhao, Yong Xu, Guangze Li, Huangwei Zhang
Summary: RYrhoCentralFoam is a hybrid Eulerian-Lagrangian solver developed based on OpenFOAM (R) for simulating detonative combustion in two-phase gas-liquid mixtures with high accuracy and diverse functionalities.
Article
Thermodynamics
Zhiwei Huang, Matthew J. Cleary, Zhuyin Ren, Huangwei Zhang
Summary: The study successfully simulated the multiple features of a supersonic lifted hydrogen jet flame using the MMC-LES approach, accurately predicting flame structure and characteristics. The importance of pressure work and viscous heating in autoignition induction and flame stabilization was highlighted in this research.
COMBUSTION AND FLAME
(2022)
Article
Mechanics
Zhiwei Huang, Huangwei Zhang
Summary: This study numerically investigates the dynamics of ethylene autoignition and deflagration-to-detonation transition (DDT) in a one-dimensional shock tube. Different combustion modes and ignition points are observed and explained.
