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Turbulent boundary layers absent mean shear

Published online by Cambridge University Press:  27 November 2017

Blair A. Johnson*
Affiliation:
Department of Civil, Architectural and Environmental Engineering, The University of Texas at Austin, Austin, TX 78712, USA
Edwin A. Cowen
Affiliation:
DeFrees Hydraulics Laboratory, School of Civil and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
*
Email address for correspondence: blairjohnson@utexas.edu

Abstract

We perform an experimental study to investigate the turbulent boundary layer above a stationary solid glass bed in the absence of mean shear. High Reynolds number $(Re_{\unicode[STIX]{x1D706}}\sim 300)$ horizontally homogeneous isotropic turbulence is generated via randomly actuated synthetic jet arrays (RASJA – Variano & Cowen J. Fluid Mech. vol. 604, 2008, pp. 1–32). Each of the arrays is controlled by a spatio-temporally varying algorithm, which in turn minimizes the formation of secondary mean flows. One array consists of an $8\times 8$ grid of jets, while the other is a $16\times 16$ array. Particle image velocimetry measurements are used to study the isotropic turbulent region and the boundary layer formed beneath as the turbulence encounters a stationary wall. The flow is characterized with statistical metrics including the mean flow and turbulent velocities, turbulent kinetic energy, integral scales and the turbulent kinetic energy transport equation, which includes the energy dissipation rate, production and turbulent transport. The empirical constant in the Tennekes (J. Fluid Mech. vol. 67, 1975, pp. 561–567) model of Eulerian frequency spectra is calculated based on the dissipation results and temporal frequency spectra from acoustic Doppler velocimetry measurements. We compare our results to prior literature that addresses mean shear free turbulent boundary layer characterizations via grid-stirred tank experiments, moving-bed experiments, rapid-distortion theory and direct numerical simulations in a forced turbulent box. By varying the operational parameters of the randomly actuated synthetic jet array, we also find that we are able to control the turbulence levels, including integral length scales and dissipation rates, by changing the mean on-times in the jet algorithm.

Type
JFM Papers
Copyright
© 2017 Cambridge University Press 

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References

Brumley, B. H. & Jirka, G. H. 1987 Near-surface turbulence in a grid-stirred tank. J. Fluid Mech. 183, 235263.CrossRefGoogle Scholar
Calmet, I. & Magnaudet, J. 2003 Statistical structure of high-Reynolds-number turbulence close to the free surface of an open-channel flow. J. Fluid Mech. 474, 355378.CrossRefGoogle Scholar
Cowen, E. A. & Monismith, S. G. 1997 A hybrid digital particle tracking velocimetry technique. Exp. Fluids 22, 199211.CrossRefGoogle Scholar
Cowen, E. A., Sou, I. M., Liu, P. L. & Raubenheimer, B. 2003 Particle image velocimetry measurements within a laboratory-generated swash zone. J. Engng Mech. ASCE 129 (10), 11191129.CrossRefGoogle Scholar
Dabiri, J. O., Bose, S., Gemmeli, B., Colin, S. P. & Costello, J. H. 2014 An algorithm to estimate unsteady and quasi-steady pressure fields from velocity field measurements. J. Expl Biol. 217, 331336.Google ScholarPubMed
De Silva, I. P. D. & Fernando, H. J. S. 1994 Oscillating grids as a source of nearly isotropic turbulence. Phys. Fluids 6, 24552464.CrossRefGoogle Scholar
Doron, P., Bertuccioli, L., Katz, J. & Osborn, T. R. 2000 Turbulence characteristics and dissipation estimates in the coastal ocean bottom boundary layer from PIV data. J. Phys. Oceanogr. 31, 21082134.2.0.CO;2>CrossRefGoogle Scholar
Efron, B. & Tibshirani, R. 1993 An Introduction to the Bootstrap. Chapman & Hall.CrossRefGoogle Scholar
Herlina, H. & Wissink, J. G. 2016 Isotropic-turbulence-induced mass transfer across a severely contaminated water surface. J. Fluid Mech. 797, 665682.CrossRefGoogle Scholar
Hopfinger, E. J. & Toly, J.-A. 1976 Spatially decaying turbulence and its relation to mixing across density interfaces. J. Fluid Mech. 78 (1), 155175.CrossRefGoogle Scholar
Hunt, J. C. R. 1984 Turbulence structure in thermal convection and shear-free boundary layers. J. Fluid Mech. 138, 161184.CrossRefGoogle Scholar
Hunt, J. C. R., Kaimal, J. C. & Gaynor, J. E. 1988 Eddy structure in the convective boundary layer: new measurements and new concepts. Q. J. R. Meteorol. Soc. 114 (482), 827858.Google Scholar
Hunt, J. & Graham, J. 1978 Free-stream turbulence near plane boundaries. J. Fluid Mech. 84, 209235.CrossRefGoogle Scholar
Johnson, B. A.2016 Turbulent boundary layers and sediment suspension absent mean flow-induced shear. PhD thesis, Cornell University.CrossRefGoogle Scholar
Khakpour, H. R., Shen, L. & Yue, D. K. P. 2011 Transport of passive scalar in turbulent shear flow under a clean or surfactant-contaminated free surface. J. Fluid Mech. 670, 527557.CrossRefGoogle Scholar
Kit, E., Fernando, J. S. & Brown, J. A. 1995 Experimental examination of Eulerian frequency spectra in zero-mean-shear turbulence. Phys. Fluids 7, 11681170.CrossRefGoogle Scholar
Liao, Q. & Cowen, E. A. 2005 An efficient anti-aliasing spectral continuous window shifting technique for PIV. Exp. Fluids 38, 197208.CrossRefGoogle Scholar
Makita, H. 1991 Realization of a large-scale turbulence field in a small wind tunnel. Fluid Dyn. Res. 8, 5364.Google Scholar
McDougall, T. 1979 Measurements of turbulence in a zero-mean-shear mixed layer. J. Fluid Mech. 94 (3), 409431.CrossRefGoogle Scholar
McKenna, S. P. & McGillis, W. R. 2004 Observations of flow repeatability and secondary circulation in an osillating grid-stirred tank. Phys. Fluids 16 (9), 34993502.CrossRefGoogle Scholar
Mydlarski, L. & Warhaft, Z. 1996 On the onset of high-Reynolds-number grid-generated wind tunnel turbulence. J. Fluid Mech. 320, 331368.CrossRefGoogle Scholar
Pao, Y.-H. 1965 Structure of turbulent velocity and scalar fields at large wavenumbers. Phys. Fluids 8 (6), 10631075.CrossRefGoogle Scholar
Perez-Alvarado, A., Mydlarski, L. & Gaskin, S. 2016 Effect of the driving algorithm on the turbulence generated by a random jet array. Exp. Fluids 57 (2), 20.CrossRefGoogle Scholar
Perot, B. & Moin, P. 1995a Shear-free turbulent boundary layers. Part 1. Physical insights into near-wall turbulence. J. Fluid Mech. 295, 199227.CrossRefGoogle Scholar
Perot, B. & Moin, P. 1995b Shear-free turbulent boundary layers. Part 2. New concepts for Reynolds stress transport equation modelling of inhomogeneous flows. J. Fluid Mech. 295, 229245.CrossRefGoogle Scholar
Peters, N. 1999 The turbulent burning velocity for large-scale and small-scale turbulence. J. Fluid Mech. 384, 107132.CrossRefGoogle Scholar
Pope, S. B. 2000 Turbulent Flows. Cambridge University Press.CrossRefGoogle Scholar
Rouse, H. & Dodu, J. 1955 Diffusion turbulente à travers une discontinuité de densité. La Houille Blanche 10, 522532.CrossRefGoogle Scholar
Shen, L., Yue, D. K. P. & Triantafyllou, G. S. 2004 Effect of surfactants on free-surface turbulent flows. J. Fluid Mech. 506, 79115.CrossRefGoogle Scholar
Spalart, P. R. 1988 Direct simulation of a turbulent boundary layer up to r = 1410. J. Fluid Mech. 187, 6198.CrossRefGoogle Scholar
Teixeira, M. A. C. & Belcher, S. E. 2000 Dissipation of shear-free turbulence near boundaries. J. Fluid Mech. 422, 167191.CrossRefGoogle Scholar
Teixeira, M. A. C. & da Silva, C. B. 2012 Turbulence dynamics near a turbulent/non-turbulent interface. J. Fluid Mech. 695, 257287.CrossRefGoogle Scholar
Tennekes, H. 1975 Eulerian and Lagrangian time microscales in isotropic turbulence. J. Fluid Mech. 67, 561567.CrossRefGoogle Scholar
Thomas, N. H. & Hancock, P. E. 1977 Grid turbulence near a moving wall. J. Fluid Mech. 82, 481496.CrossRefGoogle Scholar
Thompson, S. M. & Turner, J. S. 1975 Mixing across an interface due to turbulence generated by an oscillating grid. J. Fluid Mech. 67 (2), 349368.CrossRefGoogle Scholar
Uzkan, T. & Reynolds, W. C. 1967 A shear-free turbulent boundary layer. J. Fluid Mech. 28, 803821.CrossRefGoogle Scholar
Variano, E. A.2007 Measurements of gas transfer and turbulence at a shear-free turbulent air-water interface. PhD thesis, Cornell University.Google Scholar
Variano, E. A., Bodenschatz, E. & Cowen, E. A. 2004 A random synthetic jet array driven turbulence tank. Exp. Fluids 37, 613615.CrossRefGoogle Scholar
Variano, E. A. & Cowen, E. A. 2008 A random-jet-stirred turbulence tank. J. Fluid Mech. 604, 132.CrossRefGoogle Scholar
Variano, E. A. & Cowen, E. A. 2013 Turbulent transport of a high-Schmidt-number scalar near an air-water interface. J. Fluid Mech. 731, 259287.CrossRefGoogle Scholar
von Kármán, T. 1930 Mechanische Ähnlichkeit und Turbulenz. Nachrichten von der Gesellschaft der Wissenschaften zu Goettingen 5, 5876.Google Scholar
Westerweel, J. 1994 Efficient detection of spurious vectors in particle image velocimetry data. Exp. Fluids 16, 236247.CrossRefGoogle Scholar