Abstract
Experimental data on controlled time-periodic disturbances of the laminar flow separating at a 2D backward-facing step on a flat plate are reported. Windtunnel results were obtained at low subsonic velocity through hot-wire measurements. It is found that vorticity perturbations generated locally behind the step contaminate an extended flow region downstream and upstream of their origin. One expects this could provide a feedback involved in self-sustained oscillations of the separation bubble.
This is a preview of subscription content, log in via an institution to check access.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Alam, M., Sandham, N.D.: Direct numerical simulation of "short" laminar separation bubbles with turbulent reattachment. J. Fluid Mech. 410, 1–28 (2000)
Barkley, D., Gomes, M.G.M., Henderson, R.D.: Three-dimensional instability in flow over a backward facing step. J. Fluid Mech. 473, 167–190 (2002)
Boiko, A.V., Dovgal, A.V., Hein, S., Henning, A., Sorokin, A.: Particle image velocimetry of streaky structures in a laminar separation bubble. DLR-IB—224–2008 A 20, Goettingen (2008)
Dovgal, A.V., Sorokin, A.M.: Instability of a laminar separation bubble to vortex shedding. Thermophysics and Aeromechanics. 8, 179–186 (2001)
Gaster, M.: Stability of velocity profiles with reverse flow. In: Hussaini, M.Y., Kumar, A., Streett C.L. (eds.) Instability, Transition and Turbulence, pp. 212–215. Springer, Berlin (1992)
Hammond, D.A., Redekopp, L.G.: Local and global instability properties of separation bubbles. Eur. J. Mech. B/Fluids. 17, 145–164 (1998)
Hudy, L.M., Naguib, A., Humphreys, W.M.: Stochastic estimation of a separated-flow field using wall-pressure-array measurements. Phys. Fluids. (2007) doi: 10.1063/1.2472507
Jones, L.E., Sandberg, R.D., Sandham, N.D.: Direct numerical simulations of forced and unforced separation bubbles on an airfoil at incidence. J. Fluid Mech. 602, 175–207 (2008)
Kaiktsis, L., Monkewitz, P.A.: Global destabilization of flow over a backward-facing step. Phys. Fluids. 15, 3647–3658 (2003)
Marquillie, M., Ehrenstein, U.: On the onset of nonlinear oscillations in a separating boundary-layer flow. J. Fluid Mech. 490, 169–188 (2003)
Scarano, F., Riethmuller, M.L.: Iterative multigrid approach in PIV image processing with discrete window offset. Exp. Fluids. 26, 513–523 (1999)
Sigurdson, L.W., Roshko, A.: The structure and control of a turbulent reattaching flow. In: Liepmann, H.W., Narasimha, R. (eds.) Turbulence Management and Relaminarization, pp. 497–514. Springer, Berlin (1988)
Theofilis, V.: Advances in global linear instability analysis of nonparallel and three-dimensional flows. Progr. Aerospace Sci. 39, 249–315 (2003)
Theofilis, V., Hein, S., Dallmann, U.: On the origins of unsteadiness and three-dimensionality in a laminar separation bubble. Phil. Trans. Roy. Soc. Lond. A. 358, 3229–3246 (2000)
Wee, D., Yi, T., Annaswamy, A., Ghoniem A.F.: Self-sustained oscillations and vortex shedding in backward-facing step flows: Simulation and linear instability analysis. Phys. Fluids. 16, 3361–3373 (2004)
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2010 Springer Science+Business Media B.V.
About this paper
Cite this paper
Dovgal, A., Sorokin, A. (2010). Wave Packets of Controlled Velocity Perturbations at Laminar Flow Separation. In: Schlatter, P., Henningson, D. (eds) Seventh IUTAM Symposium on Laminar-Turbulent Transition. IUTAM Bookseries, vol 18. Springer, Dordrecht. https://doi.org/10.1007/978-90-481-3723-7_22
Download citation
DOI: https://doi.org/10.1007/978-90-481-3723-7_22
Published:
Publisher Name: Springer, Dordrecht
Print ISBN: 978-90-481-3722-0
Online ISBN: 978-90-481-3723-7
eBook Packages: EngineeringEngineering (R0)