Investigation of scramjet injection strategies for high Mach number flows

Riggins, David W.; McClinton, Charles R.; Rogers, R. C.; Bittner, Robert D.

doi:10.2514/3.23859

Cited by 60 publications

(16 citation statements)

References 6 publications

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“…The turbulent viscosity for the solution presented here is generated utilizing a simple algebraic scheme, modi ed to include injection effects. 4 More accurate predictions of turbulence diffusion quantities are desirable for future detailed studies of thrust-performance losses in engine ow elds utilizing the techniques introduced in this work. The ow eld in this study is time-averaged over an appropriate number of iterations (once minimal convergence requirements are met) to ensure a steady ow eld approximation for use in the second-law analysis presented next.…”

Section: Thrust Losses In a Multidimensional Scramjet Engine Flow Eldmentioning

confidence: 99%

“…Lewis 3 discussed the propulsive ef ciency and its relationship to energy availability and observed the inevitable difference in application between standard energy availability and obtainable thrust work (even for the ideal engine). Riggins et al 4 performed a computational investigation in which they assessed optimal combustor length in three-dimensional scramjet combustor simulations by measuring the axial distribution of the maximum thrust work availability by isentropic expansion to a reference condition ( xed area or pressure). This procedure (utilizing a xed area) for evaluating thrust work potential in a ow is also used in this work for the presentation of some of the results.…”

Section: Introductionmentioning

confidence: 99%

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Thrust Losses in Hypersonic Engines Part 2: Applications

Riggins

1997

Journal of Propulsion and Power

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for the identi cation and evaluation of the thrust losses in a scramjet engine is applied to one-dimensional scramjet engine ows with coupled loss mechanisms. Thrust and thrust potential losses are related directly to increases in irreversible entropy caused by friction, heat transfer, mixing, nonequilibrium reaction, and shocks. This method is extended to enable the evaluation of thrust losses in multidimensional ows. The fundamental relationship between performance assessment utilizing multidimensional ow elds and cycle analysis performance prediction is shown and discussed.

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Section: Thrust Losses In a Multidimensional Scramjet Engine Flow Eldmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Thrust Losses in Hypersonic Engines Part 2: Applications

Riggins

1997

Journal of Propulsion and Power

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“…3,5,6 In summary, two basic injector categories have emerged, flush wall and physical ramp. A combination of both types has also been studied.…”

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confidence: 99%

Sonic Injection into a Mach 5.0 Freestream Through Diamond Orifices

Bowersox

Fan

Lee

2004

Journal of Propulsion and Power

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An experimental study to characterize the near-field (x/d < 8.0) flow for sonic air injection through 15-deg half-angle diamond-shaped orifices at four incidence angles (10, 27.5, 45, and 90 deg) and two total pressures (0.10 and 0.46 MPa) into a high Reynolds number (53 × × 10 6 ) Mach 5.0 freestream was performed. A 90-deg circular injector, with the same exit port area and total pressures, was examined for comparative purposes. The experimental methods included surface oil flow visualization, shadowgraph photography, Mie scattering flow visualization, pressure-sensitive paint, and a pitot-cone five-hole pressure probe. Flowfield documentation, jet penetration, and shock-induced total pressure loss were derived from these data. Attachment of the interaction shock wave was found to depend on both incidence angle and injector pressure. Penetration correlations were developed for both the diamond and circular injectors. An approximate analysis indicated that the shock-induced total pressure loss decreased with decreasing incidence angle and injection pressure, and the largest losses were incurred by the 90-deg circular injector. Nomenclature= axial coordinate y = transverse coordinate y p = penetration z = lateral coordinate α = incidence angle relative to x axis, positive counterclockwise = shock standoff distance δ = boundary-layer thickness δ * = boundary-layer displacement thicknessaverage stagnation pressure ratio ρ = dsensity Subscripts c = cone surface eb = effective back j = injector max = maximum shock location n = normal ref = reference pressure, 1.0 atm

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“…A minimum total pressure loss as well as maximum efficiencies of combustion should be considered for the optimization of an overall combustor performance with the cavity installed. The definitions of η c and η loss are the same as the previous work of Riggins et al [17]. Any loss in total pressure can be correlated to a loss in thrust, thus every feasible scramjet combustor design should attempt to minimize the total pressure losses.…”

Section: Cavities Of Various L/d Ratiosmentioning

confidence: 97%