Experimental and numerical investigations of combustion mode transition in a direct–connect scramjet combustor

Xiao, Baoguo; Xing, Jianwen; Tian, Ye; Wang, Xiyao

doi:10.1016/j.ast.2015.08.001

Cited by 44 publications

(4 citation statements)

References 17 publications

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“…Direct-connect experiment and numerical simulation investigations on combustion mode transition were completed in China Aerodynamics R&D Center. [18][19][20] A novel identification method of the combustion mode was proposed based on shock train in the isolator and the threedimensional mass averaged Mach number. The combustion mode was subsonic combustion when there was a shock train in the isolator and the minimal three-dimensional mass averaged Mach number was less than 1.…”

Section: Introductionmentioning

confidence: 99%

Experimental investigation on the flame stabilization modes of liquid kerosene in a cavity-based scramjet combustor

Liu

Pan

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part G:

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The flame stabilization modes of liquid kerosene is investigated in a model scramjet combustor with flight condition of Ma 6. The effects of equivalence ratio and cavity configuration schemes on the flame stabilization modes are studied. Flame propagations and the evolution of the flow field from the ignition to the establishment of stable flame in the supersonic flow are acquired through high-speed photography and schlieren photography. Only cavity-recirculation-region stabilized combustion can be obtained in the single-cavity scramjet combustor. The intensity of combustion is weak and is termed as local ignition with low combustion efficiency. In the tandem-cavity scramjet combustor, the flame stabilization mode is largely determined by the total equivalence ratio. The flame could spread into the mainstream and even propagate against the supersonic flow as the equivalence ratio increases. The positive feedback mechanism between combustion and precombustion shock train is responsible for the evolutions of the flame stabilization modes, where the interactions between shock waves and turbulent boundary layer play a key role in the flame propagation process. The large-scale eddies in the shear layer of the upstream cavity shed at the cavity aft wall and could enhance the turbulent levels of the incoming flow of the downstream cavity. Consequently, an intense kerosene flame can be ignited in the tandem-cavity combustor. The flame could not spread to the mainstream in the single-cavity combustor due to the lower turbulence level weakening the interaction of combustion products in the recirculation zone with unburned reactants in the supersonic flow.

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Section: Introductionmentioning

confidence: 99%

Experimental investigation on the flame stabilization modes of liquid kerosene in a cavity-based scramjet combustor

Liu

Pan

et al. 2022

Proceedings of the Institution of Mechanical Engineers, Part G:

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“…A two-dimensional flow model with coaxial injection of hydrogen parallel to the air flow was considered by Tsujikawa and Northam, who also analyzed the effect of active cooling with slush hydrogen, which is a key aspect of their model [13]. Subsequently, aiming at the investigation on combustor mode transition in the combustor, Xiao [14] adopted a fully coupled form of species conservation equations and Reynolds averaged Navier-Stokes equations as a governing equation set for a chemically reacting supersonic viscous flow. A quasi-one-dimensional,…”

Section: Introductionmentioning

confidence: 99%

Modeling of Scramjet Combustors Based on Model Migration and Process Similarity

Cui

2019

Energies

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Contributed by the low cost, the simulation method is considered an attractive option for the optimization and design of the supersonic combustor. Unfortunately, accurate and satisfactory modeling is time-consuming and cost-consuming because of the complex processes and various working conditions. To address this issue, a mathematical modeling for the combustor on the basis of the clustering algorithm, machine learning algorithm, and model migration strategy is developed in this paper. A general framework for the migration strategy of the combustor model is proposed among the similar combustors, and the base model, which is developed by training the machine learning model with data from the existing combustion processes, is amended to fit the unexampled combustor using the model migration strategy with a few data. The simulation results validate the effectiveness of the development strategy, and the migrated model is proved to be suitable for the new combustor in higher accuracy with less time and calculation.

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“…Recently, Turner and Smart [15] investigated the variation in thrust and combustion efficiency of a three-dimensional scramjet engine in different modes experimentally, and they found that small changes in combustor area distribution have important effects on scramjet operability and performance. Two types of combustion mode were identified by Xiao et al [16] based on the heat release distribution of combustor and flow configuration of isolator. An improved method including finite-rate chemistry and high-temperature gas properties was proposed by Torrez et al [17] to compute the thrust of a dual-mode scramjet engine, and this method is expanded from the simple Shapiro approach.…”

Section: Introductionmentioning

confidence: 99%

Numerical investigation on the ram–scram transition mechanism in a strut-based dual-mode scramjet combustor

Huang

Yan

2016

International Journal of Hydrogen Energy

180

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The ramjet and scramjet modes can be realized in the same flowpath using the thermal choking approach, and the dual-mode scramjet combustor has attracted an increasing attention. The ram-to-scram mode transition mechanism in a strut-based dual-mode scramjet combustor has been evaluated numerically, and the influences of the inlet boundary conditions at the entrance of the isolator, the injection strategy and the jet-to-crossflow pressure ratio on the mode transition have been investigated. At the same time, the numerical approach has been validated through a turbulent diffusion combustion problem, as well as the effectiveness of the hydrogen-air chemical reaction mechanism. The obtained results show that the inlet boundary conditions at the entrance of the isolator and the jet-to-crossflow pressure ratio both have a large impact on the ram-to-scram mode transition, and the flow upstream of the strut is subsonic when the jet-to-crossflow pressure is large enough, namely 10.0 and 15.0 in the current study. The thermal choking point first appears at the leading edge of the strut, namely nearly at x = 0.25m. The low freestream Mach number is beneficial for the ramjet mode operation, and the engine would convert into the scramjet mode with the increase of the flight velocity of the vehicle. The influence of the injection strategy employed in this paper can be neglected, and the Mach number distribution upstream of the leading edge of the strut has not been disturbed. 2 Nomenclature A = cross section of the axial station where mixing is evaluated (m 2 ) or pre-exponential factor C p = specific heat (J/(kg•K)) H = height (km) k = turbulent kinetic energy (m 2 /s 2 ) Ma = Mach number M i = Mach number at the entrance of the isolator M∞ = Mach number for free stream ̇, = mixed injectant mass flow ̇, ρ = local density (kg/m 3 ) = mixing efficiency ω = specific dissipation rate parametric evaluation. Milligan et al.[18] established a baseline numerical approach to evaluate the efforts in a supersonic wind-tunnel facility at U.S. Air Force Research Laboratory (AFRL), and the detailed flow fieldinformation were not provided, as well as the information on the mode transition from the simulation aspect.Abdel-Salam and Carson [19] provided a three-dimensional numerical investigation on a dual-mode combustor, and fuel was injected through single unswept ramp. In their study, three kinds of fuel were employed, namely hydrogen, methane and ethylene, but the mode transition mechanism was not considered. The application of the computational fluid dynamics method in the simulation on the reacting flow field of a scramjet combustor would provide new and detailed information on the aspects discussed in the previous paragraphs. Thus, in the current study, the ram-to-scram mode transition mechanism in a strut-based dual mode scramjet combustor has been investigated numerically, and the influences of the inlet boundary conditions at the entrance of the isolator, the injection strategy and the jet-to-crossflow pressure ratio on the mode tra...

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Experimental and numerical investigations of combustion mode transition in a direct–connect scramjet combustor

Cited by 44 publications

References 17 publications

Experimental investigation on the flame stabilization modes of liquid kerosene in a cavity-based scramjet combustor

Experimental investigation on the flame stabilization modes of liquid kerosene in a cavity-based scramjet combustor

Modeling of Scramjet Combustors Based on Model Migration and Process Similarity

Numerical investigation on the ram–scram transition mechanism in a strut-based dual-mode scramjet combustor

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