Abstract
In the present work we investigate receptivity and disturbance amplification behind a circular roughness element in a zero-pressure-gradient flat-plate boundary layer with the aim to identify and understand the basic mechanisms at work. The low disturbance background and the high repeatability of the direct numerical simulations allow to evaluate the different contributions of acoustic-roughness receptivity and of local disturbance amplification. A distinct feature of the boundary-layer flow with roughness element are streamwise streaks which develop from the spanwise edges of the roughness. Small-scale three-dimensional disturbances develop and amplify within these streaks both by instability and by receptivity. For the present small amplitude unsteady forcing however, they remain confined to these areas. In contrast to this, the far-field receptivity result is similar to a wave train generated by periodic suction and blowing at the wall.
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
Maucher, U., Rist, U., and Wagner, S., 1997, A method for the identification of high-frequency oscillations in unsteady flows, Z. Angew. Math. Mech. 77, Suppl. 1, S2094–S210.
Peskin C.S., 1977, Numerical analysis of blood flow in the heart, J. Comp. Phys. 25:220–252.
Rist, U., and Fasel, H.F., 1995, Direct numerical simulation of controlled transition in a flat-plate boundary layer, J. Fluid Mech. 298:211-248.
Stemmer, C., and Kloker, M., 2000, Later stages of transition in an airfoil boundary layer flow, in:Laminar-Turbulent Transition, Proc. IUTAM-Symp. Sedona, Az, Sept. 13-17, 1999, H.F. Fasel, W.S. Saric, eds., Springer, New York, Heidelberg, pp. 499–504.
Wagner S., Kloker M., and Rist U. (Eds.), 2003, Recent Results in Laminar-Turbulent Transition-Selected Numerical and Experimental Contributions from the DFG-Verbundschwerpunktprogramm “Transition” in Germany, NNFM 86, Springer, Heidelberg.
Wörner, A., 2004, Numerische Untersuchungen zum Entstehungsprozess von Grenzschichtstörungen durch die Interaktion von Schallwellen mit Oberflächenrauhigkeiten, Dissertation Universität Stuttgart, Shaker, Aachen.
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2006 Springer
About this paper
Cite this paper
Rist, U., Jäger, A. (2006). UNSTEADY DISTURBANCE GENERATION AND AMPLIFICATION IN THE BOUNDARY-LAYER FLOW BEHIND A MEDIUM-SIZED ROUGHNESS ELEMENT. In: Govindarajan, R. (eds) IUTAM Symposium on Laminar-Turbulent Transition. Fluid Mechanics and Its Applications, vol 78. Springer, Dordrecht. https://doi.org/10.1007/1-4020-4159-4_40
Download citation
DOI: https://doi.org/10.1007/1-4020-4159-4_40
Publisher Name: Springer, Dordrecht
Print ISBN: 978-1-4020-3459-6
Online ISBN: 978-1-4020-4159-4
eBook Packages: EngineeringEngineering (R0)