On hypersonic boundary-layer stability

Stetson, Kenneth F.; Kimmel, Roger L.

doi:10.2514/6.1992-737

Cited by 195 publications

(90 citation statements)

References 15 publications

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“…The wavelength of these waves is measured to be approximately twice the boundary layer thickness. These waves occur in wave packets and are associated with second mode disturbances 2,6 . The second mode disturbances are first detected at about R=2025 according to a closer examination of the video records used to construct Fig.…”

Section: Schlieren Datamentioning

confidence: 99%

Hypersonic boundary layer stability over a flared cone in a quiet tunnel

Lachowicz

Chokani

Wilkinson

1996

34th Aerospace Sciences Meeting and Exhibit

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Hypersonic boundary layer measurements were conducted over a flared cone in a quiet wind tunnel. The flared cone was tested at a freestream unit Reynolds number of 2.82x10 6 /ft in a Mach 6 flow. This Reynolds number provided laminar-to-transitional flow over the model in a low-disturbance environment. Point measurements with a single hot wire using a novel constant voltage anemometry system were used to measure the boundary layer disturbances. Surface temperature and schlieren measurements were also conducted to characterize the laminar-to-transitional state of the boundary layer and to identify instability modes. Results suggest that the second mode disturbances were the most unstable and scaled with the boundary layer thickness. The integrated growth rates of the second mode compared well with linear stability theory in the linear stability regime. The second mode is responsible for transition onset despite the existence of a second mode sub-harmonic. The sub-harmonic wavelength also scales with the boundary layer thickness. Furthermore, the existence of higher harmonics of the fundamental suggests that non-linear disturbances are not associated with "high" free stream disturbance levels. Nomenclature

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Section: Schlieren Datamentioning

confidence: 99%

Hypersonic boundary layer stability over a flared cone in a quiet tunnel

Lachowicz

Chokani

Wilkinson

1996

34th Aerospace Sciences Meeting and Exhibit

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“…In contrast to the unstable oblique first mode in low speed boundary layer flow, the twodimensional second Mack mode dominates in hypersonic boundary layers, which has been confirmed by the experiments of hypersonic boundary-layer flows over sharp or blunt cones. [3][4][5] Stetson et al 4 carried out experiments to study the hypersonic boundary layer stability of a blunt cone with 7°half-angle and zero angle of attack, and fluctuation spectra at different locations were measured. Stetson's experiments show that the unstable second modes are dominant disturbance waves with significant superharmonic waves.…”

Section: Introductionmentioning

confidence: 99%

Direct numerical simulation of hypersonic boundary layer transition over a blunt cone with a small angle of attack

2010

Physics of Fluids

125

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The direct numerical simulation of boundary layer transition over a 5°half-cone-angle blunt cone is performed. The free-stream Mach number is 6 and the angle of attack is 1°. Random wall blow-and-suction perturbations are used to trigger the transition. Different from the authors' previous work ͓Li et al., AIAA J. 46, 2899 ͑2008͔͒, the whole boundary layer flow over the cone is simulated ͑while in the author's previous work, only two 45°regions around the leeward and the windward sections are simulated͒. The transition location on the cone surface is determined through the rapid increase in skin fraction coefficient ͑C f ͒. The transition line on the cone surface shows a nonmonotonic curve and the transition is delayed in the range of 20°Յ Յ 30°͑ = 0°is the leeward section͒. The mechanism of the delayed transition is studied by using joint frequency spectrum analysis and linear stability theory ͑LST͒. It is shown that the growth rates of unstable waves of the second mode are suppressed in the range of 20°Յ Յ 30°, which leads to the delayed transition location. Very low frequency waves ͑VLFWs͒ are found in the time series recorded just before the transition location, and the periodic times of VLFWs are about one order larger than those of ordinary Mack second mode waves. Band-pass filter is used to analyze the low frequency waves, and they are deemed as the effect of large scale nonlinear perturbations triggered by LST waves when they are strong enough.

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“…24 of Ref. [45]). Data was also acquired at a higher pressure, to record data into transition onset.…”

Section: General Informationmentioning

confidence: 91%

“…Stetson et al carried out calibrated measurements of instability wave growth on several conical models in AEDC Tunnel B at Mach 8, during the late 1970's and early 1980's [44,45]. Detailed hotwire measurements were carried out in this expensive production tunnel by J. Donaldson, under the direction of K. Stetson [46,47].…”

Section: General Informationmentioning

confidence: 99%

Hypersonic laminar instability on round cones near zero angle of attack

Schneider

2001

39th Aerospace Sciences Meeting and Exhibit

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Reliable predictions for hypersonic laminarturbulent transition will have to be based on simulation of the transition mechanisms. Accurate simulation of the second-mode instability-wave growth on a round cone at zero angle of attack would be a significant step toward this goal. Hypersonic stability experiments in this geometry are reviewed, and three are selected. Extensive and previously unpublished data from Stetson's sharp and blunt cone experiments are reported. Approximate computations were carried out using inviscid-boundary-layer and e N methods. The experimental results are compared to previous high-accuracy computations and to the present approximate computations. Quantitative agreement is at present insufficient for reliable e N predictions. The difficulties with both experiment and computation are described.

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On hypersonic boundary-layer stability

Cited by 195 publications

References 15 publications

Hypersonic boundary layer stability over a flared cone in a quiet tunnel

Hypersonic boundary layer stability over a flared cone in a quiet tunnel

Direct numerical simulation of hypersonic boundary layer transition over a blunt cone with a small angle of attack

Hypersonic laminar instability on round cones near zero angle of attack

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