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Characteristics of drag-reduced turbulent boundary layers with pulsed-direct-current plasma actuation

Published online by Cambridge University Press:  29 March 2021

Alan H. Duong
Affiliation:
Institute for Flow Physics and Control, Aerospace and Mechanical Engineering Department, University of Notre Dame, Notre Dame, IN46556, USA
Thomas C. Corke*
Affiliation:
Institute for Flow Physics and Control, Aerospace and Mechanical Engineering Department, University of Notre Dame, Notre Dame, IN46556, USA
Flint O. Thomas
Affiliation:
Institute for Flow Physics and Control, Aerospace and Mechanical Engineering Department, University of Notre Dame, Notre Dame, IN46556, USA
*
Email address for correspondence: tcorke@nd.edu

Abstract

Experiments were performed using an active flow control approach that has shown the ability to significantly reduce the viscous drag in turbulent boundary layers. The purpose of this work was to document the changes in the turbulence characteristics of the boundary layer with the drag reduction. The flow control involved generating a steady spanwise velocity component of the order of $u_{\tau }$, within the sublayer using an array of pulsed-DC plasma actuators. The intent was to reduce the wall-normal vorticity component, $\omega _y$, that is associated with the mean flow distortion caused by quasi-steady streamwise vorticity associated with the wall streak structure first observed by Kline et al. (J. Fluid Mech., vol. 30, 1967, pp. 741–773). The significance of the $\omega _y$ comes from Schoppa & Hussain (J. Fluid Mech., vol. 453, 2002, pp. 57–108), who proposed an autonomous mechanism for self-sustained wall turbulence generation of which the sublayer wall-normal vorticity component is a critical parameter. The results document the characteristics of a turbulent boundary layer in which the viscous drag was reduced by 68 %. This involved measurements of the $u$ and $v$ velocity components in a three-dimensional region within the boundary layer using a pair of dual (X) hot-wire probes. Under the reduced drag, these documented a decrease in $u$ and $v$ turbulence intensity levels through most of the boundary layer. When scaled by $u_{\tau }$, the impact on the $v$ fluctuations was larger than that on the $u$ fluctuations. Analysis based on [$uv$] quadrant splitting documented a decrease in duration, and an increase in the time between ‘ejections’ (Q2) and ‘sweep’ (Q4) events that substantially lowered the near-wall turbulence production in the drag-reduced boundary layers. Conditional averages used to reconstruct the two- and three-dimensional coherent motions including $\lambda _2$ vortical structures, indicate a suppression of coherent features in the wall layer. These results are consistent with an underlying mechanism for drag reduction that comes from a suppression of the turbulence producing events in the wall layer associated with the wall streak structure.

Type
JFM Papers
Copyright
© The Author(s), 2021. Published by Cambridge University Press

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References

REFERENCES

Antonia, R. 1972 Conditional sampled measurements near the outer edge of a turbulent boundary layer. J. Fluid Mech. 56 (1), 118.CrossRefGoogle Scholar
Baars, W., Squire, D., Talluru, K., Abbassi, M., Hutchins, N. & Marusic, I. 2016 Wall-drag measurements of smooth-and rough-wall turbulent boundary layers using a floating element. Exp. Fluids 57, 90.CrossRefGoogle Scholar
Baron, A. & Quadrio, M. 1996 Turbulent drag reduction by spanwise wall oscillations. Appl. Sci. Res. 55, 311326.CrossRefGoogle Scholar
Blackwelder, R. & Kaplan, R. 1976 On the wall structure of the turbulent boundary layer. J. Fluid Mech. 76 (1), 89112.CrossRefGoogle Scholar
Canton, J., Orlu, R., Chin, C., Hutchins, N., Monty, J. & Schlatter, P. 2016 On large-scale friction control in turbulent wall flow in low Reynolds number channels. Flow Turbul. Combust. 97 (3), 811827.CrossRefGoogle Scholar
Choi, J., Chun-Xiao, X. & Sung, H. 2002 Drag reduction by spanwise wall oscillation in wall-bounded turbulent flows. AIAA J. 40 (5), 842850.CrossRefGoogle Scholar
Choi, K-S. & Clayton, B.R. 2001 The mechanism of turbulent drag reduction with wall oscillation. Intl J. Heat Fluid Flow 22, 19.CrossRefGoogle Scholar
Corino, E.R. & Brodkey, R.S. 1969 A visual investigation of the wall region in turbulent flow. J. Fluid Mech. 1, 130.CrossRefGoogle Scholar
Corke, T.C., Enloe, C.L. & Wilkinson, S.P. 2010 Dielectric barrier discharge plasma actuators for flow control. Annu. Rev. Fluid Mech. 42, 505529.CrossRefGoogle Scholar
Corke, T.C. & Thomas, F.O. 2018 Active and passive turbulent boundary layer drag reduction. AIAA J. 55 (10), 38353847.CrossRefGoogle Scholar
Dhanak, M. & Si, C. 1999 On reduction of turbulent wall friction through spanwise oscillations. J. Fluid Mech. 383, 175195.CrossRefGoogle Scholar
Du, Y. & Karniadakis, G. 2000 Suppressing wall turbulence via a transverse traveling wave. Science 288, 12301234.CrossRefGoogle Scholar
Du, Y. & Karniadakis, G. 2002 Drag reduction in wall-bounded turbulence via a transverse traveling wave. J. Fluid Mech. 457, 134.CrossRefGoogle Scholar
Duong, A.H. 2019 Active turbulent boundary layer control: an experimental evaluation of viscous drag reduction using pulsed-dc plasma actuators. PhD thesis, University of Notre Dame.Google Scholar
Duong, A., Midya, S., Corke, T., Hussain, F. & Thomas, F. 2019 Turbulent boundary layer drag reduction using pulsed-DC plasma actuation. In Proceedings of the 11th International Symposium on Turbulence and Shear Flow Phenomena, Southampton, UK.Google Scholar
Jasinski, C. & Corke, T.C. 2020 Mechanism for increased viscous drag over porous sheet acoustic liners. AIAA J. 58 (8), 33933404.CrossRefGoogle Scholar
Jeong, J. & Hussain, F. 1995 On the identification of a vortex. J. Fluid Mech. 285, 6994.CrossRefGoogle Scholar
Kim, J. 2011 Physics and control of wall turbulence for drag reduction. Phil. Trans. R. Soc. A 369, 13961411.CrossRefGoogle ScholarPubMed
Klebanoff, P.S. 1955 Characteristics of turbulence in a boundary layer with zero pressure gradient. NACA Tech Rep. NACA-TR-1247. National Advisory Committee for Aeronautics.Google Scholar
Kline, S., Reynolds, W., Schraub, F. & Runstadler, P. 1967 The structure of turbulent boundary layers. J. Fluid Mech. 30, 741773.CrossRefGoogle Scholar
Laufer, J. & Narayanan, M. 1971 Mean period of the turbulent production mechanism in a boundary layer. Phys. Fluids 14, 182.CrossRefGoogle Scholar
Lu, S. & Willmarth, W. 1973 a Measurements of the structure of the Reynolds stress in a turbulent boundary layer. J. Fluid Mech. 60, 481511.CrossRefGoogle Scholar
Lu, S.S. & Willmarth, W.W. 1973 b Measurement of the structure of the Reynolds stress in a turbulent boundary layer. J. Fluid Mech. 60, 481581.CrossRefGoogle Scholar
Nagib, H. & Chauhan, K. 2008 Variations of von Karman coefficient in canonical flows. Phys. Fluids 20, 101518.CrossRefGoogle Scholar
Schoppa, W. & Hussain, F. 1998 A large-scale control strategy for drag reduction in turbulent boundary layers. Phys. Fluids 10, 1049.CrossRefGoogle Scholar
Schoppa, W. & Hussain, F. 2002 Coherent structure generation on near-wall turbulence. J. Fluid Mech. 453, 57108.CrossRefGoogle Scholar
de Silva, C., Hutchins, N. & Marusic, I. 2016 Uniform momentum zones in turbulent boundary layers. J. Fluid Mech. 786, 309331.CrossRefGoogle Scholar
Thomas, F.O., Corke, T.C., Duong, A., Midya, S. & Yates, K. 2019 Turbulent drag reduction using pulsed-dc plasma actuation. J. Phys. D: Appl. Phys. 52, 434001.CrossRefGoogle Scholar
Trujillo, S., Bogard, D. & Ball, K. 1997 Turbulent boundary layer drag reduction using an oscillating wall. AIAA Paper 97-187. American Institute of Aeronautics and Astronautics.CrossRefGoogle Scholar
Yao, J., Chen, X., Thomas, F. & Hussain, F. 2017 Large-scale control for drag reduction in turbulent channel flows. Phys. Rev. Fluids 2, 062601.CrossRefGoogle Scholar