Protuberance Boundary Layer Transition for Project Orion Crew Entry Vehicle

Amar, Adam J.; Horvath, Thomas J.; Hollis, Brian R.; Berger, Karen T.; Berry, Scott A.; Calvert, Nathan D.

doi:10.2514/6.2008-1227

Cited by 25 publications

(24 citation statements)

References 18 publications

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“…17 Based upon the computed axisymmetric meanflow, the trip is located at around 45% of the CEV radius from the center where the boundary-layer edge Mach number is about 0.3, as opposed to an estimated edge Mach number of about 0.8 for the trip E location in Ref. 17. The roughness height is estimated to be 0.1466 mm and the cylinder diameter is 1.128 mm, using the same k/D ratio of 0.13 as in the experiment.…”

Section: Cev Configurations and Boundary Conditionsmentioning

confidence: 99%

“…The trip location is set to give the same k/δ value as the trip E at the same wind-tunnel condition in the experiment. 17 Based upon the computed axisymmetric meanflow, the trip is located at around 45% of the CEV radius from the center where the boundary-layer edge Mach number is about 0.3, as opposed to an estimated edge Mach number of about 0.8 for the trip E location in Ref. 17.…”

Section: Cev Configurations and Boundary Conditionsmentioning

confidence: 99%

“…2 has been experimentally investigated in the NASA Langley Research Center, 20-inch Mach 6 tunnel. 17 The pizza-box shape protuberance array was used to trip the laminar boundary layers at several wind tunnel conditions. Measured surface heating data along the symmetry axis was used to determine the corresponding transition locations.…”

Section: Cev Configurations and Boundary Conditionsmentioning

confidence: 99%

See 2 more Smart Citations

Effects of Cavities and Protuberances on Transition over Hypersonic Vehicles

Chang

Choudhari

et al. 2011

41st AIAA Fluid Dynamics Conference and Exhibit

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Surface protuberances and cavities on a hypersonic vehicle are known to cause several aerodynamic or aerothermodynamic issues. Most important of all, premature transition due to these surface irregularities can lead to a significant rise in surface heating. To help understand laminar-turbulent transition induced by protuberances or cavities on a Crew Exploration Vehicle (CEV) surface, high-fidelity numerical simulations are carried out for both types of trips on a CEV wind tunnel model. Due to the large bluntness, these surface irregularities reside in an accelerating subsonic boundary layer. For the Mach 6 wind tunnel conditions with a roughness Reynolds number Re kk of 800, it was found that a protuberance with a height to boundary layer thickness ratio of 0.73 leads to strong wake instability and spontaneous vortex shedding, while a cavity with identical geometry only causes a rather weak flow unsteadiness. The same cavity with a larger Reynolds number also leads to similar spontaneous vortex shedding and wake instability. The wake development and the formation of hairpin vortices for both protuberance and cavity were found to be qualitatively similar to that observed for an isolated hemisphere submerged in a subsonic, low speed flat-plate boundary layer. However, the shed vortices and their accompanying instability waves were found to be slightly stabilized downstream by the accelerating boundary layer along the CEV surface. Despite this stabilizing influence, it was found that the wake instability spreads substantially in both wall-normal and azimuthal directions as the flow is evolving towards a transitional state. Similarities and differences between the wake instability behind a protuberance and a cavity are investigated. Computations for the Mach 6 boundary layer over a slender cylindrical roughness element with a height to the boundary layer thickness of about 1.1 also shows spontaneous vortex shedding and strong wake instability. Comparisons of detailed flow structures associated with protuberances at subsonic and supersonic edge Mach numbers indicate distinctively different instability mechanisms. Nomenclature

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Section: Cev Configurations and Boundary Conditionsmentioning

confidence: 99%

Section: Cev Configurations and Boundary Conditionsmentioning

confidence: 99%

Section: Cev Configurations and Boundary Conditionsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of Cavities and Protuberances on Transition over Hypersonic Vehicles

Chang

Choudhari

et al. 2011

41st AIAA Fluid Dynamics Conference and Exhibit

View full text Add to dashboard Cite

show abstract

“…However, these data, as well as subsequent test data obtained with a wider range of trip parameters are discussed from the perspective of boundary-layer transition criteria in Ref. 4.…”

Section: Tripped Boundary-layer Datamentioning

confidence: 99%

Aeroheating Testing and Predictions for Project Orion CEV at Turbulent Conditions

Hollis

Berger

Horvath

et al. 2008

46th AIAA Aerospace Sciences Meeting and Exhibit

Self Cite

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Inch Mach 6 Air Tunnel. Laminar and turbulent predictions were generated for all wind tunnel test conditions and comparisons were performed with the experimental data to help define the accuracy of computational method. In general, it was found that both laminar data and predictions, and turbulent data and predictions, agreed to within less than the estimated ±12% experimental uncertainty estimate. Laminar heating distributions from all three data sets were shown to correlate well and demonstrated Reynolds numbers independence when expressed in terms of the Stanton number based on adiabatic wallrecovery enthalpy. Transition onset locations on the leeside centerline were determined from the data and correlated in terms of boundary-layer parameters. Finally turbulent heating augmentation ratios were determined for several body-point locations and correlated in terms of the boundary-layer momentum Reynolds number. = free stream Mach number Me = boundary-layer edge Mach number

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“…20) and Test 6932 (Ref. 21) was a study of the effects of boundary-layer tripping on both the forebody and aftbody of the model. Runs were performed in both static and continuous pitch-mode over an angle-of-attack range of 16-deg to 32-deg free stream Reynolds numbers of 2.1×10 6 /ft to 7.3×10 6 /ft.…”

Section: Tests 6931 and 6932 -Boundary-layer Trippingmentioning

confidence: 99%

Protuberance Boundary Layer Transition for Project Orion Crew Entry Vehicle

Cited by 25 publications

References 18 publications

Effects of Cavities and Protuberances on Transition over Hypersonic Vehicles

Effects of Cavities and Protuberances on Transition over Hypersonic Vehicles

Aeroheating Testing and Predictions for Project Orion CEV at Turbulent Conditions

Blunt-Body Entry Vehicle Aerothermodynamics: Transition and Turbulence on the CEV and MSL Configurations

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