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    View Video Presentation: https://doi.org/10.2514/6.2021-3536.vid The combustion performances in a 4.5 Mach cavity-flame holding axisymmetric scramjet fueled by ethylene are numerically investigated by LES (Large Eddy Simulation) with 97.05 million cells and DZFM (Dynamic Zone Flamelet model) with 210*91 flamelet zones. A detailed chemical reaction mechanism consisting of 66 irreversible reactions between 23 species is used for more accurate simulation. In this study, the combustion dynamics in the scramjet and the flame stabilization mechanism of the cavity are emphatically analyzed and the performance of the scramjet engine is evaluated.
    Scramjet
    Large-Eddy Simulation
    Citations (1)
    The development of hypersonic aspirated propulsion systems, such as scramjet engines, represents a great technological challenge, mainly due to the complex aerothermodynamic processes observed during flight in a sensitive atmosphere. In this context, on-site tests, involving direct and indirect measurements of parameters associated with the exposure of systems and subsystems to hypersonic flight conditions, are an essential step for projects of an innovative nature. In this sense, the present work aimed to evaluate the parameters of supersonic combustion optimization in scramjet models, using flows produced in the T1 Hypersonic Shock Tunnel, installed at the Institute of Advanced Studies, IEAv. This study investigated the flame production, retention and stabilization characteristics in a hydrogen-fed scramjet combustor with backwall expansion cavities at Mach 2.6 inlet condition with stagnation pressure of 3.3 MPa and stagnation temperature of 2100 K. The effects of two flameholder geometries were compared. The experimental results showed that the flameholder with the shortest length and height had the best combustion performance, with a 15% increase in burning efficiency. However, the study of other geometries will be of fundamental importance for the determination of the influence of each parameter in the retention and stabilization of the flame, as well as the optimal configuration of the combustor.
    Scramjet
    Stagnation pressure
    Ramjet
    Stagnation temperature
    Citations (0)
    Multi-strut injection is an approach to increase the overall performance of Scramjet while reducing the risk of thermal choking in a supersonic combustor. Hence computational simulation of Scramjet combustor at Mach 2.5 through multiple central lobed struts (three struts) have been presented and discussed in the present research article. The geometry and model used here is slight modification of the DLR (German Aerospace Center) scramjet model. Present results show that the presence of three struts injector improves the performance of scramjet combustor as compared to single strut injector. The combustion efficiency is also found to be highest in case of three strut fuel injection system. In order to validate the results, the numerical data for single strut injection is compared with experimental result which is taken from the literature.
    Scramjet
    Citations (49)
    One-dimensional code for the computation of the scramjet flowpath is developed by adding the source terms for the area variation, friction,mass addition and chemical heat release to the quasi-one-dimensional Euler equations.The thrust and friction forces as well as the parameters variations along the axis direction and the exit parameters of the scramjet were given in a short time.Validated by the computation of the reacting flow of NAL's dual mode scramjet model,the influences of the expanding angles of the isolator and the combustor,the location and the means of the fuel injection,the two methods to solve the chemical heat release term,the isolator height to the performance of the scramjet fueled by kerosene are analyzed.The scramjet configuration with good performance with steady shock for the flying vehicle design can be demonstrated.
    Scramjet
    Isolator
    Ramjet
    Citations (4)
    A computationally efficient quasi-one-dimensional model is needed to facilitate designs of scramjet engines.A universal quasi-one-dimensional hypersonic propulsion model was developed which is applicable to both gas and liquid hydrocarbon fueled scramjets with isolators and transonic flow.Euler equations are used to analyze the effects of combustor cross sectional area variation,evaporation of liquid fuels,fuel mass addition,friction and the oblique shock train in the isolator.The model was evaluated against three scramjet experiments with various fuels,the hydrogen-fueled NAL dual-mode scramjet,a supercritical kerosene-fueled scramjet and a liquid kerosene-fueled scramjet.The effectiveness and accuracy of the model were validated by good agreement between the predictions and experimental data.Thus,this scramjet propulsion model can be used for configuration design and parameter optimization with different kinds of fuels.
    Scramjet
    Isolator
    Ramjet
    Citations (2)
    The nationally-recognized Susquehanna Chorale will delight audiences of all ages with a diverse mix of classic and contemporary pieces. The ChoraleAƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚¢AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚€AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚™s performances have been described as AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚¢AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚€AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚œemotionally unfiltered, honest music making, successful in their aim to make the audience feel, to be moved, to be part of the performance - and all this while working at an extremely high musical level.AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚¢AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚€AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚ƒAƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚ƒAƒÂƒA‚‚AƒÂ‚A‚‚AƒÂƒA‚ƒAƒÂ‚A‚‚AƒÂƒA‚‚AƒÂ‚A‚ Experience choral singing that will take you to new heights!
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    Scramjets are proposed as a second stage for a multi-stage access-to-space system. At present the upper limit of scramjet operation is expected to be Mach 12-14. Use of oxygen enrichment is a possible method for increasing the speed and altitude of scramjet operation. This paper involves mission analysis of scramjets using oxygen enrichment. It follows on from Smart & Tetlow [5], in which trajectory studies of a threestage rocket-scramjet-rocket access-to-space system were conducted. These calculations indicated that the net thrust (scramjet thrust - vehicle drag) of a hypersonic vehicle with three scramjet engine modules was reduced to very low levels above Mach 12. The current work examines the use of oxygen enrichment in the scramjet to increase net thrust above Mach 10. Results of the study indicate that an important effect of oxygen enrichment is to allow scramjet powered vehicle operation at higher altitude.
    Scramjet
    Rocket (weapon)
    Hypersonic flight
    Citations (1)