Flight Data Analysis of the HYSHOT 2

Hass, Neal E.; Smart, Michael K.; Paull, A.

doi:10.2514/6.2005-3354

Cited by 12 publications

(6 citation statements)

References 4 publications

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“…18). As the jet shear layer developed downstream, local extinction and re-ignition appear in the windward shear layer, which is consistent with the observations in the experiment by Gamba et al [7]. In addition, combustion also appears in the recirculation zone upstream of the jet orifice, which is related to the flame stabilization in the supersonic transverse jet combustion at higher jet to cross-flow flux ratios.…”

Section: ) Jet To Cross-flow Flux Ratio J = 211supporting

confidence: 89%

“…Transverse jet in supersonic cross-flow (JISCF) is one of the most fundamental flow phenomena in supersonic combustion chambers [1][2][3][4][5], such as the actual flight vehicle Hyshot II [6,7] and the supersonic combustion experiments by Gamba et al [8,9]. In JISCF combustion chambers, there exist complex shock train, flame, turbulence and boundary layer interactions [6][7][8][9][10][11][12][13][14][15]. In addition to auto-ignition due to high-enthalpy and shock aerodynamic heating, local extinction caused by turbulent small-scale vortex and re-ignition, there is also strong coupling between the density, pressure, temperature and velocity.…”

Section: Introductionmentioning

confidence: 99%

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Large-Eddy Simulations of Transverse Jet Mixing and Flame Stability in Supersonic Crossflow

Zhao

2021

AIAA Journal

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Large-eddy simulations (LES) combined with Partially Stirred Reactor (PaSR) combustion model are employed to investigate the turbulent mixing, combustion mode and flame stability of a sonic hydrogen jet injecting into high-enthalpy supersonic crossflow at three momentum flux ratios J, i.e. 0.71, 2.11 and 4.00, respectively. The LES accuracy in terms of the turbulent kinetic energy, power spectra density and sub-grid Damköhler number is carefully addressed against various LES resolution criteria and the experimental mean pressure distribution on the upper wall. The ignition processes with auto-ignition and shock compression effects are identified and analyzed. At J = 0.71, the shock-induced ignition occurs behind the reflected shock wave and the combustion heat release is dominated by the premixed combustion. While for the high jet to cross-flow momentum flux ratios, e.g., J = 2.11 and 4.00, ignition happens toward around the jet orifice due to the strong bow shock and reflected shock effects and the combustion heat releases are dominated by the non-premixed combustion. Furthermore, the mechanisms of flame stabilization, local extinction and re-ignition in the transverse jet combustion in supersonic cross-flow are further analyzed with the chemical explosive mode analysis (CEMA).

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Section: ) Jet To Cross-flow Flux Ratio J = 211supporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Large-Eddy Simulations of Transverse Jet Mixing and Flame Stability in Supersonic Crossflow

Zhao

2021

AIAA Journal

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“…The HyShot II model scramjet has been the subject of many studies. Experimentally, both flight [1,2] and ground [3,4] measurements have provided useful data on the operation of highspeed air-breathing vehicles. However, many critical aspects of the combustion processes are not directly accessible to experimental measurements.…”

mentioning

confidence: 99%

Reynolds-Averaged Navier-Stokes Simulations of the HyShot II Scramjet

et al. 2012

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The internal flow in the HyShot II scramjet is investigated through numerical simulations. A computational infrastructure to solve the compressible Reynolds-averaged Navier-Stokes equations on unstructured meshes is introduced. A combustion model based on tabulated chemistry is considered to incorporate detailed chemicalkinetics mechanics while retaining a low computational cost. Both nonreactive and reactive simulations have been performed, and results are compared with ground test measurements obtained at DLR, German Aerospace Center. Different turbulence models were tested, and the dependence on the mesh is assessed through grid refinement. The comparison with experimental data shows good agreement, although the computed heat fluxes at the wall are higher than measurements for the reactive case. A sensitivity analysis on the turbulent Schmidt and Prandtl numbers shows that the choice of these parameters has a strong influence on the results. In particular, variations of the turbulent Prandtl number lead to large changes in the heat flux at the walls. Finally, the inception of thermal choking is investigated by increasing the equivalence ratio, whereby a normal shock is created locally and moves upstream, leading to a large increase in the maximum pressure. Nevertheless, a large portion of the flow is still supersonic. Nomenclatureproportionality constant between turbulence and scalar time scales c p = specific heat capacity at constant pressure D = scalar diffusion coefficient d = injector diameter E = total specific energy e = specific internal energy F = convective flux vector F v = viscous flux vector h = specific enthalpy I = identity matrix k = turbulent kinetic energy Le = Lewis number Ma = Mach number N = number of species n = outward-pointing unit vector normal to surface P ref = reference pressure Pr = Prandtl number p = pressure Q = vector of primitives variables Q ref = reference wall heat flux R = residuum R = gas constant R u = universal gas constant r f = vector connecting cell center and center of cell face S = source-term vector S = wave speed in approximate Riemann solver S i = source term for scalar i Sc = Schmidt number T = temperature t = time U = vector of conserved variables U = inflow velocity V = cell volume v = Cartesian velocity vector W = species molecular weight x = Cartesian position vector Y = species mass fraction y = wall-normal direction Z = mixture fraction = exponent for the pressure correction of the source term of the progress variable = ratio of specific heat capacity h 0 = heat of formation ij = Kronecker delta @ = boundary of the physical domain = thermal diffusivity = viscosity = approximation of the triple correlation = stress tensor = density k = turbulent kinetic-energy Schmidt number ij = viscous stress tensor R ij = Reynolds stress tensor = generic scalar ' = equivalence ratio = scalar dissipation rate = slope limiter = physical domain ! = specific turbulent dissipation _ ! C = source term of the progress variable Subscripts F = fuel f = cell face inj = injector k ...

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“…Supersonic combustion engines (scramjets) are an economic alternative to rockets because they do not require on-board storage of the oxidizer. The HyShot II scramjet, shown in Figure 1, was designed to demonstrate supersonic combustion during flight in a simple configuration [24,53], and it has since been the subject of multiple ground-based experimental campaigns in the High Enthalpy shock tunnel Göttingen (HEG) of the German Aerospace Center (DLR) [18,19,22,23,[33][34][35][36]51]. The simplicity of the configuration and the availability of experimental data has made the HyShot II scramjet the subject of multiple computational investigations, based on either Reynolds-averaged Navier-Stokes (RANS) simulations [46] or large-eddy simulations (LES) [5,17,32].…”

Section: Introductionmentioning

confidence: 99%

Exploiting active subspaces to quantify uncertainty in the numerical simulation of the HyShot II scramjet

Constantine

Emory

Larsson

et al. 2015

Journal of Computational Physics

137

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We present a computational analysis of the reactive flow in a hypersonic scramjet engine with focus on effects of uncertainties in the operating conditions. We employ a novel methodology based on active subspaces to characterize the effects of the input uncertainty on the scramjet performance. The active subspace identifies one-dimensional structure in the map from simulation inputs to quantity of interest that allows us to reparameterize the operating conditions; instead of seven physical parameters, we can use a single derived active variable. This dimension reduction enables otherwise infeasible uncertainty quantification, considering the simulation cost of roughly 9500 CPU-hours per run. For two values of the fuel injection rate, we use a total of 68 simulations to (i) identify the parameters that contribute the most to the variation in the output quantity of interest, (ii) estimate upper and lower bounds on the quantity of interest, (iii) classify sets of operating conditions as safe or unsafe corresponding to a threshold on the output quantity of interest, and (iv) estimate a cumulative distribution function for the quantity of interest.

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Flight Data Analysis of the HYSHOT 2

Cited by 12 publications

References 4 publications

Large-Eddy Simulations of Transverse Jet Mixing and Flame Stability in Supersonic Crossflow

Large-Eddy Simulations of Transverse Jet Mixing and Flame Stability in Supersonic Crossflow

Reynolds-Averaged Navier-Stokes Simulations of the HyShot II Scramjet

Exploiting active subspaces to quantify uncertainty in the numerical simulation of the HyShot II scramjet

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