Penetration of Gaseous Jets in Supersonic Flows

Portz, Ron; Segal, Corin

doi:10.2514/1.23541

Cited by 86 publications

(29 citation statements)

References 6 publications

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“…The well-known lower trailing CVP is shown in figure 1(b) which has been depicted in many literatures. Many experimental investigations have been conducted to understand the mechanisms of a jet injected into a supersonic crossflow, which include detailed velocity measurements (Santiago & Dutton 1997), time-averaged wall-pressure measurements (Everett et al 1998), the jet penetration height (Portz & Segal 2006) and temporally-resolved flow visualizations (Gruber et al 1997;Sun et al 2013) and mixing characteristics (Ben-Yakar et al 2006;Gamba & Mungal 2015) with non-reactive and combustible gaseous jets. These measurements showed the overall jet flow features and the dynamics of the jet shear layer and shock interactions with boundary layers.…”

Section: Introductionmentioning

confidence: 99%

Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow

Sun

2018

J. Fluid Mech.

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Direct numerical simulations were conducted to uncover physical aspects of a transverse sonic jet injected into a supersonic crossflow at a Mach number of 2.7. Simulations were carried out for two different jet-to-crossflow momentum flux ratios (J ) of 2.3 and 5.5. It is identified that collision shock waves behind the jet induce a herringbone separation bubble in the near-wall jet wake and a reattachment valley is formed and embayed by the herringbone recirculation zone. The recirculating flow in the jet leeward separation bubble forms a primary TCVP (trailing counter-rotating vortex pair) close to the wall surface. Analysis on streamlines passing the separation region shows that the wing of the herringbone separation bubble serves as a micro-ramp vortex generator and streamlines acquire rotating momentum downstream to form a secondary surface TCVP in the reattachment valley. Herringbone separation wings disappear in the farfield due to the cross interaction of lateral supersonic flow and the expansion flow in the reattachment valley, which also leads to the vanishing of the secondary TCVP. A three-dimensional schematic of surface trailing wakes is presented and explains formation mechanism of the surface TCVPs. (a) x/D=3.5 for J =5.5 and x/D=3.5 for J =2.3 (b) x/D=8 for J =5.5 and x/D=5.5 for J =2.3 (c) x/D=12 for J =5.5 and x/D=8 for J =2.3 (d) x/D=18 for J =5.5 and x/D=12 for J =2.3 Figure 11. Contours of the mean flow streamwise velocity and streamlines on cross planes of J =5.5 and J =2.3, isolines of u/U∞=0.0 are superimposed

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Section: Introductionmentioning

confidence: 99%

Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow

Sun

2018

J. Fluid Mech.

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“…The trailing upper vortex is weaker than the other vorticities hence more difficult to identify. the jet injection into a supersonic crossflow, which include detailed velocity measurements [6] , timeaveraged wall-pressure measurements [7] , penetration height [8] , temporally resolved flow visualizations [9,10] and mixing characteristics [3] with nonreactive and combustible gaseous jets [4] .…”

Section: Introductionmentioning

confidence: 99%

Generation of Upper Trailing Counter-Rotating Vortices of a Sonic Jet in a Supersonic Crossflow

Sun

2018

AIAA Journal

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Direct numerical simulations were conducted to investigate physical structures of a transverse sonic air jet injected into a supersonic air crossflow at a Mach number of 2.7. Simulations were run for two different jet-to-crossflow momentum flux ratios (J) of 1.85 and 5.5. The main averaged flow features around the transverse jet, such as major counter rotating vortices (CRVs) and trailing CRVs (TCRVs) were captured. The major CRVs form in the lateral portion of the jet plume and absorb other induced trailing vortices downstream of the jet plume. Upper trailing CRVs form above the major CRVs downstream of the jet barrel shock. The streamline analysis indicates that the upper trailing CRVs are related to the Mach disk. As the streamlines penetrate the lateral side of Mach disk where a strong shear condition exists, the baroclinic torque induces upper vorticities in the opposite rotating direction against the major CRVs. Downstream of the Mach disk, the baroclinic vorticity production along the streamlines tends to approach zero, which means no more torque is pumped into the farfield and the upper TCRVs are merged into the major CRVs by their suction. Keywords: supersonic flow; transverse jet; direct numerical simulation; counter rotating vortices; upper trailing counter rotating vortices Nomenclature J =jet-to-crossflow momentum flux ratio BVP = baroclinic vorticity production CRV = counter rotating vortices DNS =direct numerical simulation JISC =jet interaction with supersonic crossflow LES =large eddy simulation STBL =supersonic turbulent boundary layer TCRV =trailing counter rotating vortices

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“…8. The work from these researchers was selected for comparison with the present study for being experimental investigations of gaseous fuel injection into a similar Mach number crossflow, as suggested by Portz and Segal [20]. Although the experimental results in this work lie within the results obtained by other authors, some discrepancies exist that can be attributed to several factors, including differences in the definition of the penetration boundary, measurement technique, and experimental conditions.…”

Section: Propertymentioning

confidence: 85%

“…(1)], although it is also sensitive to other parameters such as boundary-layer thickness and freestream Mach number to a lesser extent [20,21]:…”

mentioning

confidence: 99%

Supersonic Mixing Enhancement Using Fin-Guided Fuel Injection

Aguilera

2015

Journal of Propulsion and Power

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The mixing flowfields of transverse walled fuel injection with and without the guidance of a fin in a Mach 2.2 flow were experimentally characterized and compared. This study evaluated the ability of fin-guided injection to enhance fuel-air mixing while reducing shock-induced stagnation pressure losses. The nonreacting gaseous injection experiments used helium as a hydrogen surrogate and simulated four mass flow rate conditions to investigate the performance of the proposed injection scheme with variable jet momentum. The analysis of schlieren visualizations demonstrated a 100-200% increase in jet penetration for the fin-guided cases over the baseline 12 diameters downstream of the injection point. Wall pressure measurements were correlated to the schlieren results which showed that the strength of the jet-induced shock in the baseline was reduced by 33-47% by using the fin. A planar-Mie scattering method used to obtain cross-sectional views of the injection flowfields revealed that the fin was not only responsible for raising the fuel jet away from the wall but also enabled its vertical spreading. The present results demonstrate that this fin geometry can enhance mixing via increased penetration and spreading, reduce the strength of jet-induced shocks, and potentially displace the reaction zone away from the combustor wall. Nomenclature A = area D = injector orifice diameter h, l, w = height, length, and width, respectively J = jet to freestream momentum ratio M = Mach number _ m = mass flow rate P = pressure Re = Reynolds number r = injector orifice radius T = temperature u = velocity x, y, z = x, y, z coordinate directions, respectively Δ = Delta δ = shock deflection angle ρ = density τ = tunnel steady-state time 0 = stagnation condition Subscripts B, F = baseline and fin guided, respectively blo = blockage, for blockage area inj = injector j = jet p = injector proximity ts = test section 1 = condition upstream of jet-induced shock 2 = condition downstream of jet-induced shock 3 = combustor inlet condition ∞ = freestream

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Penetration of Gaseous Jets in Supersonic Flows

Cited by 86 publications

References 6 publications

Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow

Formation of surface trailing counter-rotating vortex pairs downstream of a sonic jet in a supersonic cross-flow

Generation of Upper Trailing Counter-Rotating Vortices of a Sonic Jet in a Supersonic Crossflow

Supersonic Mixing Enhancement Using Fin-Guided Fuel Injection

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