Experimental, analytical, and computational methods applied to hypersonic compression ramp flows

Simeonides, G.; Haase, Werner; Manna, M.

doi:10.2514/3.11985

Cited by 53 publications

(15 citation statements)

References 9 publications

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“…The peaks in pressure and heat transfer seem more pronounced for condition G, which suggests a greater spreading of the compression waves and hence a larger separated region than conditions B and D. Also, in view of its higher Reynolds number, the growth length of the reattaching boundary layer may be smaller for condition G than for conditions B and D, which could also explain the relatively higher heat transfer (Simeonides et al 1994).…”

Section: Corner Angle = 18 •mentioning

confidence: 90%

“…The subscript fp refers to the flat-plate value at the location corresponding to the peak value. Simeonides et al (1994) recognized that for separated flows, the growth length scale of the reattaching boundary layer, L pk , plays an important role in determining the level of peak heating for separated flows. The peak heating for separated flows was shown to be given by…”

Section: General Features Of Compression Corner Flowmentioning

confidence: 99%

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The interaction of a shock wave with a laminar boundary layer at a compression corner in high-enthalpy flows including real gas effects

1997

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The high-enthalpy, hypersonic flow over a compression corner has been examined experimentally and theoretically. Surface static pressure and heat transfer distributions, along with some flow visualization data, were obtained in a free-piston shock tunnel operating at enthalpies ranging from 3 MJ kg−1 to 19 MJ kg−1, with the Mach number varying from 7.5 to 9.0 and the Reynolds number based on upstream fetch from 2.7×104 to 2.7×105. The flow was laminar throughout. The experimental data compared well with theories valid for perfect gas flow and with other relevant low-to-moderate enthalpy data, suggesting that for the current experimental conditions, the real gas effects on shock wave/boundary layer interaction are negligible. The flat-plate similarity theory has been extended to include equilibrium real gas effects. While this theory is not applicable to the current experimental conditions, it has been employed here to determine the potential maximum effect of real gas behaviour. For the flat plate, only small differences between perfect gas and equilibrium gas flows are predicted, consistent with experimental observations. For the compression corner, a more rapid rise to the maximum pressure and heat transfer on the ramp face is predicted in the real gas flows, with the pressure lying slightly below, and the heat transfer slightly above, the perfect gas prediction. The increase in peak heat transfer is attributed to the reduction in boundary layer displacement thickness due to real gas effects.

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Section: Corner Angle = 18 •mentioning

confidence: 90%

Section: General Features Of Compression Corner Flowmentioning

confidence: 99%

The interaction of a shock wave with a laminar boundary layer at a compression corner in high-enthalpy flows including real gas effects

1997

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“…Computations often underpredict the length of separation, 16,[81][82][83][84] but some authors report predictions that both underestimate and overestimate experimental L sep depending on the numerical grid or depending on the experiment simulated. [85][86][87][88] Though it has been noted that the computed position of separation generally moves upstream with increased grid resolution, 89 both Grasso et al 86 and Rizzetta and Mach 87 have clearly demonstrated that the solution depends not just on the overall grid resolution, as characterized by the number of cells in each spatial direction, but also on exactly how those cells are distributed. Results can be extremely sensitive to such parameters as the spatial distribution of cells in the interaction region, and the aspect ratio of cells at the leading edge, at separation, and at reattachment.…”

Section: Viscous Double-wedge Computationsmentioning

confidence: 99%

Separation length in high-enthalpy shock/boundary-layer interaction

Davis

Sturtevant

2000

Physics of Fluids

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Experiments were performed in the T5 Hypervelocity Shock Tunnel to investigate nonequilibrium real-gas effects on separation length using a double-wedge geometry and nitrogen test gas. Local external flow conditions were estimated by computing the inviscid nonequilibrium flow field. A new scaling parameter was developed to approximately account for wall temperature effects on separation length for a laminar nonreacting boundary layer and arbitrary viscosity law. A classification was introduced to divide mechanisms for real-gas effects into those acting internal and external to viscous regions of the flow. Internal mechanisms were further subdivided into those arising upstream and downstream of separation. Analysis based on the ideal dissociating gas model and a scaling law for separation length of a nonreacting boundary layer showed that external mechanisms due to dissociation may decrease separation length at low incidence but depend on the free-stream dissociation at high incidence. A limited numerical study of reacting boundary layers showed that internal mechanisms due to recombination occurring in the boundary layer upstream of separation cause a slight decrease in separation length relative to a nonreacting boundary layer with the same external conditions. Correlations were obtained of experimentally measured separation length using local external flow parameters computed for reacting flow, which scales out external mechanisms but not internal mechanisms. These showed the importance of the new scaling parameter in high-enthalpy flows, a linear relationship between separation length and reattachment pressure ratio, and a Reynolds-number effect for transitional interactions. A significant increase in scaled separation length was observed in the experimental data at high enthalpy. The increase was attributed to an internal mechanism arising from recombination in the free-shear layer downstream of separation, perhaps altering its velocity profile. This real-gas effect depends on the combined presence of free-stream dissociation and a cold wall.

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“…In addition to the numerical results, experimental data were obtained from the literature, Refs. [54][55][56][57][58][59][60], and these residts are presented in Tables A.2 The preceding results indicate that the upstream influence associated with ramp flowfields is different from that of shock impingement flowfields. This is due in part to the fact that the boundary layer induces a small turning angle which produces an effective increase in pressure change for shock impingement flowfields and an effective decrease in pressure change for ramp flowfields.…”

Section: Ipns Regionmentioning

confidence: 99%

PNS algorithm for solving supersonic flows with upstream influences

Miller

Tannehill

Lawrence

1998

36th AIAA Aerospace Sciences Meeting and Exhibit

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This manuscript has been reproduced from the microfilm master. UMI films the text direct^ from the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter fiice, i;^e others may be from any type of computer primer. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletioiL Oversize materials (e.g., maps, drawings, charts) are reproduced by sectioning the original, b^inning at the upper left-hand comer and continuing from left to right in equal sections with small overijq)s. Each original is also photographed in one exposure and is included in reduced form at the back of the book.

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Experimental, analytical, and computational methods applied to hypersonic compression ramp flows

Cited by 53 publications

References 9 publications

The interaction of a shock wave with a laminar boundary layer at a compression corner in high-enthalpy flows including real gas effects

The interaction of a shock wave with a laminar boundary layer at a compression corner in high-enthalpy flows including real gas effects

Separation length in high-enthalpy shock/boundary-layer interaction

PNS algorithm for solving supersonic flows with upstream influences

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