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Conditional statistics and flow structures in turbulent boundary layers buffeted by free-stream disturbances

Published online by Cambridge University Press:  13 March 2019

Jiho You
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
Tamer A. Zaki*
Affiliation:
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA
*
Email address for correspondence: [email protected]

Abstract

Direct numerical simulations are performed to study zero-pressure-gradient turbulent boundary layers beneath quiescent and vortical free streams. The inflow boundary layer is computed in a precursor simulation of laminar-to-turbulence transition, and the free-stream vortical forcing is obtained from direct numerical simulations of homogeneous isotropic turbulence. A level-set approach is employed in order to objectively distinguish the boundary-layer and free-stream fluids, and to accurately evaluate their respective contributions to flow statistics. When free-stream turbulence is present, the skin friction coefficient is elevated relative to its value in the canonical boundary-layer configuration. An explanation is provided in terms of an increase in the power input into production of boundary-layer turbulence kinetic energy. This increase takes place deeper than the extent of penetration of the external perturbations towards the wall, and also despite the free-stream perturbations being void of any Reynolds shear stress. Conditional statistics demonstrate that the free-stream turbulence has two effects on the boundary layer: one direct and the other indirect. The low-frequency components of the free-stream turbulence penetrate the logarithmic layer. The associated wall-normal Reynolds stress acts against the mean shear to enhance the shear stress, which in turn enhances turbulence production. This effect directly enlarges the scale and enhances the energy of outer large-scale motions in the boundary layer. The second, indirect effect is the influence of these newly formed large-scale structures. They modulate the near-wall shear stress and, as a result, increase the turbulence kinetic energy production in the buffer layer, which is deeper than the extent of penetration of free-stream turbulence towards the wall.

Type
JFM Papers
Copyright
© 2019 Cambridge University Press 

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References

Ames, F. E. & Moffat, R. J.1990 Heat transfer with high intensity, large scale turbulence: the flat plate turbulent boundary layer and the cylindrical stagnation point. Stanford University Rep., pp. HMT–44.Google Scholar
Batchelor, G. K. 1953 The Theory of Homogeneous Turbulence. Cambridge University Press.Google Scholar
Bernardini, M. & Pirozzoli, S. 2011 Inner/outer layer interactions in turbulent boundary layers: a refined measure for the large-scale amplitude modulation mechanism. Phys. Fluids 23, 061701.Google Scholar
Bisset, D. K., Hunt, J. C. R. & Rogers, M. M. 2002 The turbulent/non-turbulent interface bounding a far wake. J. Fluid Mech. 451, 383410.Google Scholar
Blair, M. F. 1983 Influence of free-stream turbulence on turbulent boundary layer heat transfer and mean profile development. Part I. Experimental data. Trans. ASME: J. Heat Transfer 105, 3340.Google Scholar
Borrell, G. & Jiménez, J. 2016 Properties of the turbulent/non-turbulent interface in boundary layers. J. Fluid Mech. 801, 554596.Google Scholar
Brzek, B., Torres-Nieves, S., Lebrón, J., Cal, R., Meneveau, C. & Castillo, L. 2009 Effects of free-stream turbulence on rough surface turbulent boundary layers. J. Fluid Mech. 635, 207243.Google Scholar
Castro, I. P. 1984 Effects of free-stream turbulence on low Reynolds number boundary layers. Trans. ASME: J. Fluids Engng 106, 298306.Google Scholar
Cheung, L. C. & Zaki, T. A. 2010 Linear and nonlinear instability waves in spatially developing two-phase mixing layers. Phys. Fluids 22, 052103.Google Scholar
Cheung, L. C. & Zaki, T. A. 2011 A nonlinear PSE method for two-fluid shear flows with complex interfacial topology. J. Comput. Phys. 230 (17), 67566777.Google Scholar
Desjardins, O., Moureau, V. & Pitsch, H. 2008 An accurate conservative level set/ghost fluid method for simulating turbulent atomization. J. Comput. Phys. 227, 83958416.Google Scholar
Dogan, E., Hanson, R. E. & Ganapathisubramani, B. 2016 Interactions of large-scale free-stream turbulence with turbulent boundary layers. J. Fluid Mech. 802, 79107.Google Scholar
Dogan, E., Hearst, R. J. & Ganapathisubramani, B. 2017 Modelling high Reynolds number wall-turbulence interactions in laboratory experiments using large-scale free-stream turbulence. Phil. Trans. R. Soc. Lond. A 375 (2089), 20160091.Google Scholar
Esteban, L., Dogan, E., Rodríguez-López, E. & Ganapathisubramani, B. 2017 Skin-friction measurements in a turbulent boundary layer under the influence of free-stream turbulence. Exp. Fluids 58, 115.Google Scholar
Ganapathisubramani, B., Hutchins, N., Hambleton, W. T. & Longmire, E. K. 2005 Investigation of large-scale coherence in a turbulent boundary layer using two-point correlations. J. Fluid Mech. 524, 5780.Google Scholar
Hancock, P. E. & Bradshaw, P. 1983 The effect of free-stream turbulence on turbulent boundary layers. Trans. ASME: J. Fluids Engng 105, 284289.Google Scholar
Hancock, P. E. & Bradshaw, P. 1989 Turbulence structure of a boundary layer beneath a turbulent free stream. J. Fluid Mech. 205, 4576.Google Scholar
Hearst, R. J., Dogan, E. & Ganapathisubramani, B. 2018 Robust features of a turbulent boundary layer subjected to high-intensity free-stream turbulence. J. Fluid Mech. 851, 416435.Google Scholar
Hunt, J. C. R. & Durbin, P. A. 1999 Perturbed vortical layers and shear sheltering. Fluid Dyn. Res. 24 (6), 375404.Google Scholar
Hutchins, N. & Marusic, I. 2007 Evidence of very long meandering features in the logarithmic region of turbulent boundary layers. J. Fluid Mech. 579, 128.Google Scholar
Hwang, J., Lee, J., Sung, H. J. & Zaki, T. A. 2016 Inner–outer interactions of large-scale structures in turbulent channel flow. J. Fluid Mech. 790, 128157.Google Scholar
Jelly, T. O., Jung, S. Y. & Zaki, T. A. 2014 Turbulence and skin friction modification in channel flow with streamwise-aligned superhydrophobic surface texture. Phys. Fluids 26, 095102.Google Scholar
Jiménez, J., Hoyas, S., Simens, M. P. & Mizuno, Y. 2010 Turbulent boundary layers and channels at moderate Reynolds numbers. J. Fluid Mech. 657, 335360.Google Scholar
Jung, S. Y. & Zaki, T. A. 2015 The effect of a low-viscosity near-wall film on bypass transition in boundary layers. J. Fluid Mech. 772, 330360.Google Scholar
Lee, J., Jung, S. Y., Sung, H. J. & Zaki, T. A. 2013 Effect of wall heating on turbulent boundary layers with temperature-dependent viscosity. J. Fluid Mech. 726, 196225.Google Scholar
Lee, J., Sung, H. J. & Zaki, T. A. 2017 Signature of large-scale motions on turbulent/non-turbulent interface in boundary layers. J. Fluid Mech. 819, 165187.Google Scholar
Li, Q., Schlatter, P. & Henningson, D. S. 2010 Simulations of heat transfer in a boundary layer subject to free-stream turbulence. J. Turbul. 11 (45), 133.Google Scholar
Mathis, R., Hutchins, N. & Marusic, I. 2009 Large-scale amplitude modulation of the small-scale structures in turbulent boundary layers. J. Fluid Mech. 628, 311337.Google Scholar
Nagata, K., Sakai, Y. & Komori, S. 2011 Effects of small-scale freestream turbulence on turbulent boundary layers with and without thermal convection. Phys. Fluids 23, 065111.Google Scholar
Nagib, H. M., Chauhan, K. A. & Monkewitz, P. A. 2007 Approach to an asymptotic state for zero pressure gradient turbulent boundary layers. Phil. Trans. R. Soc. Lond. A 365, 755770.Google Scholar
Nolan, K. P. & Zaki, T. A. 2013 Conditional sampling of transitional boundary layers in pressure gradients. J. Fluid Mech. 728, 306339.Google Scholar
Osher, S. & Sethian, J. A. 1988 Fronts propagating with curvature-dependent speed: algorithms based on Hamilton–Jacobi formulations. J. Comput. Phys. 79, 1249.Google Scholar
Péneau, F., Boisson, H. C. & Djilali, N. 2000 Large eddy simulation of the influence of high free-stream turbulence on a spatially evolving boundary layer. Intl J. Heat Fluid Flow 21, 640647.Google Scholar
Peng, D., Merriman, B., Osher, S., Zhao, H. & Kang, M. 1999 A PDE-based fast local level set method. J. Comput. Phys. 155 (2), 410438.Google Scholar
Pope, S. B. 2000 Turbulent Flows. Cambridge University Press.Google Scholar
Renard, N. & Deck, S. 2016 A theoretical decomposition of mean skin friction generation into physical phenomena across the boundary layer. J. Fluid Mech. 790, 339367.Google Scholar
Rosenfeld, M., Kwak, D. & Vinokur, M. 1991 A fractional step solution method for the unsteady incompressible Navier–Stokes equations in generalized coordinate systems. J. Comput. Phys. 94, 102137.Google Scholar
Schlatter, P., Li, Q., Brethouwer, G., Johansson, A. V. & Henningson, D. S. 2010 Simulations of spatially evolving turbulent boundary layers up to Re 𝜃 = 4300. Intl J. Heat Fluid Flow 31, 251261.Google Scholar
Schlatter, P. & Örlü, R. 2010 Assessment of direct numerical simulation data of turbulent boundary layers. J. Fluid Mech. 659, 116126.Google Scholar
Schlatter, P. & Örlü, R. 2012 Turbulent boundary layers at moderate Reynolds numbers: inflow length and tripping effects. J. Fluid Mech. 710, 534.Google Scholar
Sharp, N. S., Neuscamman, S. & Warhaft, Z. 2009 Effects of large-scale free stream turbulence on a turbulent boundary layer. Phys. Fluids 21, 095105.Google Scholar
da Silva, C. B., Hunt, J. C. R., Eames, I. & Westerweel, J. 2014 Interfacial layers between regions of different turbulence intensity. Annu. Rev. Fluid Mech. 46, 567590.Google Scholar
Simonich, J. C. & Bradshaw, P. 1978 Effect of free-stream turbulence on heat transfer through a turbulent boundary layer. Trans. ASME: J. Heat Transfer 100, 671677.Google Scholar
Thole, K. A. & Bogard, D. G. 1995 Enhanced heat transfer and shear stress due to high free-stream turbulence. Trans. ASME: J. Turbomach. 117, 418424.Google Scholar
Thole, K. A. & Bogard, D. G. 1996 High freestream turbulence effects on turbulent boundary layers. Trans. ASME: J. Fluids Engng 118, 276284.Google Scholar
Wallace, J. M. 2016 Quadrant analysis in turbulence research: history and evolution. Annu. Rev. Fluid Mech. 48, 131158.Google Scholar
Zaki, T. A. & Durbin, P. A. 2005 Mode interaction and the bypass route to transition. J. Fluid Mech. 531, 85111.Google Scholar
Zaki, T. A. & Saha, S. 2009 On shear sheltering and the structure of vortical modes in single- and two-fluid boundary layers. J. Fluid Mech. 626, 111147.Google Scholar
Zalesak, S. T. 1979 Fully multi-dimensional flux-corrected transport algorithms for fluids. J. Comput. Phys. 31, 335362.Google Scholar