Hostname: page-component-586b7cd67f-2brh9 Total loading time: 0 Render date: 2024-11-28T05:48:51.807Z Has data issue: false hasContentIssue false
  • English
  • Français

Interaction of second-mode disturbances with an incipiently separated compression-corner flow

Published online by Cambridge University Press:  04 March 2021

Cameron S. Butler  and
Stuart J. Laurence Open the ORCID record for Stuart J. Laurence [Opens in a new window]
Cameron S. Butler
Affiliation:
Department of Aerospace Engineering, University of Maryland–College Park, College Park, MD20742, USA
Stuart J. Laurence*
Affiliation:
Department of Aerospace Engineering, University of Maryland–College Park, College Park, MD20742, USA
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

An experimental campaign was conducted to examine the impact of an abrupt change in surface geometry on hypersonic boundary-layer instability waves. The primary test configuration consisted of a $5^{\circ }$ half-angle, nominally sharp cone with a $15^{\circ }$ half-angle flare attachment. Tests were conducted at Mach 6 with the unit Reynolds number varying from $3.0\times 10^6$ to $4.9\times 10^6\ \textrm {m}^{-1}$. The $10^{\circ }$ compression was sufficient to create a small separation region at the cone–flare junction at these conditions. Ultra-high-speed schlieren (822 kHz) revealed the propagation of second-mode disturbances with frequencies between 200 and 300 kHz within the upstream boundary layer; when these reached the separation region, radiation of disturbance energy along the separation shock was observed. Tests conducted at low unit Reynolds numbers demonstrated inhibited instability growth (compared to the straight-cone case) through the separation region and the development of low-frequency (${\sim }75\ \textrm {kHz}$) instabilities within the separated shear layer. At higher Reynolds numbers, however, the corner interaction was found to cause rapid breakdown near reattachment, leading to earlier transition than for a straight cone. Analysis of the schlieren images using spectral proper orthogonal decomposition provided a global picture of the structure and development of the second-mode and shear-generated instabilities.

JFM classification

Aerodynamics: High-speed flow Boundary Layers: Boundary layer stability Compressible Flows: Compressible boundary layers
Type
JFM Rapids
Information
Journal of Fluid Mechanics , Volume 913 , 25 April 2021 , R4
Check for updates
Copyright
© The Author(s), 2021. Published by Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Balakumar, P., Zhao, H. & Atkins, H. 2005 Stability of hypersonic boundary-layers over a compression corner. AIAA J. 43 (4), 760–767.CrossRefGoogle Scholar
Benay, R., Chanetz, B., Mangin, B., Vandomme, L. & Perraud, J. 2006 Shock wave/transitional boundary-layer interactions in hypersonic flow. AIAA J. 44 (6), 1243–1254.CrossRefGoogle Scholar
Benitez, E.K., Jewell, J.S., Schneider, S.P. & Esquieu, S. 2020 Instability measurements on an axisymmetric separation bubble at Mach 6. AIAA Paper 2020-3072.CrossRefGoogle Scholar
Butler, C. & Laurence, S.J. 2019 HyperTERP: a newly commissioned hypersonic shock tunnel at the University of Maryland. AIAA Paper 2019-2860.CrossRefGoogle Scholar
Fedorov, A. 2011 Transition and stability of high-speed boundary-layers. Annu. Rev. Fluid Mech. 43, 79–95.CrossRefGoogle Scholar
Guiho, F., Alizard, F. & Robinet, J.-C. 2016 Instabilities in oblique shock wave/laminar boundary-layer interactions. J. Fluid Mech. 789, 1–35.CrossRefGoogle Scholar
Hargather, M. & Settles, G. 2012 A comparison of three quantitative Schlieren techniques. Opt. Laser Engng 50, 8–17.CrossRefGoogle Scholar
Heffner, K.S., Chpoun, A. & Lengrand, J.C. 1993 Experimental study of transitional axisymmetric shock-boundary-layer interactions at Mach 5. AIAA Paper 93-3131.CrossRefGoogle Scholar
Kennedy, R.E., Laurence, S.J., Smith, M.S. & Marineau, E.C. 2018 Investigation of the second-mode instability at Mach 14 using calibrated Schlieren. J. Fluid Mech. 845, R2.CrossRefGoogle Scholar
Mack, L.M. 1975 Linear stability theory and the problem of supersonic boundary-layer transition. AIAA J. 13 (3), 278–289.CrossRefGoogle Scholar
Novikov, A., Egorov, I. & Fedorov, A. 2016 Direct numerical simulation of wave packets in hypersonic compression corner flow. AIAA J. 54 (7), 2034–2050.CrossRefGoogle Scholar
Ort, D. & Dosch, J. 2019 Influence of mounting on the accuracy of piezoelectric pressure measurements for hypersonic boundary-layer transition. AIAA Paper 2019-2292.CrossRefGoogle Scholar
Roghelia, A., Olivier, H., Egorov, I. & Chuvakhov, P. 2017 Experimental investigation of Gortler vortices in hypersonic ramp flows. Exp. Fluids 58, 139.CrossRefGoogle Scholar
Running, C.L., Juliano, T.J., Jewell, J.S., Borg, M.P. & Kimmel, R.L. 2018 Hypersonic shock-wave/boundary-layer interactions on a cone/flare model. AIAA Paper 2018-3702.CrossRefGoogle Scholar
Sawaya, J., Sassanis, V., Yassir, S. & Sescu, A. 2018 Assessment of the impact of two-dimensional wall deformation shape on high-speed boundary-layer disturbances. AIAA J. 56 (12), 4787–4800.CrossRefGoogle Scholar
Sidharth, G., Dwivedi, A., Candler, G. & Nichols, J. 2018 Onset of three-dimensionality in supersonic flow over a slender double wedge. Phys. Rev. Fluids 3, 093901.Google Scholar
Towne, A., Schmidt, O.T. & Colonius, T. 2018 Spectral proper orthogonal decomposition and its relationship to dynamic mode decomposition and resolvent analysis. J. Fluid Mech. 847, 821–867.CrossRefGoogle Scholar

Butler and Laurence supplementary movie 1

Test-time image sequence for condition Re30: (Top) Raw images, (top-middle) reference-subtracted images, (bottom-middle) 175-275 kHz bandpass-filtered images and (bottom) 70-86 kHz bandpass-filtered images.

Download Butler and Laurence supplementary movie 1(Video)
Video 47 MB

Butler and Laurence supplementary movie 2

Test-time image sequence for condition Re42: (Top) Raw images, (top-middle) reference-subtracted images, (bottom-middle) 200-300 kHz bandpass-filtered images and (bottom) 76-92 kHz bandpass-filtered images.

Download Butler and Laurence supplementary movie 2(Video)
Video 49 MB

Butler and Laurence supplementary movie 3

Test-time image sequence for condition Re49: (Top) Raw images, (top-middle) reference-subtracted images, (bottom-middle) 225-325 kHz bandpass-filtered images and (bottom) 82-98 kHz bandpass-filtered images.

Download Butler and Laurence supplementary movie 3(Video)
Video 43.3 MB

Butler and Laurence supplementary movie 4

Average PSD computed for individual frequencies at (top) condition Re30, (middle) condition Re42 and (bottom) condition Re49.

Download Butler and Laurence supplementary movie 4(Video)
Video 4.1 MB