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Optimal fluxes and Reynolds stresses

Published online by Cambridge University Press:  15 November 2016

Javier Jiménez*
Affiliation:
School of Aeronautics, Universidad Politécnica de Madrid, 28040 Madrid, Spain
*
Email address for correspondence: [email protected]

Abstract

It is remarked that fluxes in conservation laws, such as the Reynolds stresses in the momentum equation of turbulent shear flows, or the spectral energy flux in anisotropic turbulence, are only defined up to an arbitrary solenoidal field. While this is not usually significant for long-time averages, it becomes important when fluxes are modelled locally in large-eddy simulations, or in the analysis of intermittency and cascades. As an example, a numerical procedure is introduced to compute fluxes in scalar conservation equations in such a way that their total integrated magnitude is minimised. The result is an irrotational vector field that derives from a potential, thus minimising sterile flux ‘circuits’. The algorithm is generalised to tensor fluxes and applied to the transfer of momentum in a turbulent channel. The resulting instantaneous Reynolds stresses are compared with their traditional expressions, and found to be substantially different. This suggests that some of the alleged shortcomings of simple subgrid models may be representational artefacts, and that the same may be true of the intermittency properties of the turbulent stresses.

Type
Papers
Copyright
© 2016 Cambridge University Press 

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References

del Álamo, J. C., Jiménez, J., Zandonade, P. & Moser, R. D. 2004 Scaling of the energy spectra of turbulent channels. J. Fluid Mech. 500, 135144.Google Scholar
Antonia, R. A. & Atkinson, J. D. 1973 High-order moments of Reynolds shear stress fluctuations in a turbulent boundary layer. J. Fluid Mech. 58, 581593.Google Scholar
Bardina, J.1983 Improved turbulence models based on large eddy simulation of homogeneous, incompressible, turbulence flows. PhD thesis, Thermosciences Division, Department of Mechanical Engineering, Stanford University.Google Scholar
Barut, A. O. 1980 Electrodynamics and Classical Theory of Fields and Particles. Dover.Google Scholar
Cimarelli, A. & De Angelis, E. 2011 Analysis of the Kolmogorov equation for filtered wall-turbulent flows. J. Fluid Mech. 676, 376395.Google Scholar
Cimarelli, A. & De Angelis, E. 2012 Anisotropic dynamics and sub-grid energy transfer in wall-turbulence. Phys. Fluids 24, 015102.Google Scholar
Dar, G., Verma, M. K. & Eswaran, V. 2001 Energy transfer in two-dimensional magnetohydrodynamic turbulence: formalism and numerical results. Physica D 157, 207225.Google Scholar
Domaradzki, J. A. & Rogallo, R. S. 1990 Local energy transfer and nonlocal interactions in homogeneous, isotropic turbulence. Phys. Fluids A 2, 413426.Google Scholar
Gelfand, I. M. & Fomin, S. V. 1963 Calculus of Variations. Prentice-Hall.Google Scholar
Germano, M., Piomelli, U., Moin, P. & Cabot, W. 1991 A dynamic subgrid-scale eddy viscosity model. Phys. Fluids A 3, 17601765.Google Scholar
Hill, R. J. 2002 Exact second-order structure–function relationships. J. Fluid Mech. 468, 317326.Google Scholar
Jackson, J. D. 2002 From Lorenz to Coulomb and other explicit gauge transformations. Am. J. Phys. 70, 917928.Google Scholar
Jiménez, J. 2012 Cascades in wall-bounded turbulence. Annu. Rev. Fluid Mech. 44, 2745.Google Scholar
Jiménez, J. 2013a How linear is wall-bounded turbulence? Phys. Fluids 25, 110814.Google Scholar
Jiménez, J. 2013b Near-wall turbulence. Phys. Fluids 25, 101302.Google Scholar
Kim, J., Moin, P. & Moser, R. D. 1987 Turbulence statistics in fully developed channel flow at low Reynolds number. J. Fluid Mech. 177, 133166.Google Scholar
Kolmogorov, A. N. 1941 The local structure of turbulence in incompressible viscous fluids at very large Reynolds numbers. Dokl. Akad. Nauk. SSSR 30, 301305; reprinted in Proc. R. Soc. Lond. A 434, 9–13 (1991).Google Scholar
Kraichnan, R. H. 1971 Inertial range transfer in two- and three-dimensional turbulence. J. Fluid Mech. 47, 525535.CrossRefGoogle Scholar
Landau, L. D. & Lifshitz, E. M. 1958 Fluid Mechanics, 2nd edn, chap. 10, Addison-Wesley.Google Scholar
Lozano-Durán, A., Flores, O. & Jiménez, J. 2012 The three-dimensional structure of momentum transfer in turbulent channels. J. Fluid Mech. 694, 100130.Google Scholar
Lozano-Durán, A. & Jiménez, J. 2014 Time-resolved evolution of coherent structures in turbulent channels: characterization of eddies and cascades. J. Fluid Mech. 759, 432471.Google Scholar
Lu, S. S. & Willmarth, W. W. 1973 Measurements of the structure of the Reynolds stress in a turbulent boundary layer. J. Fluid Mech. 60, 481511.Google Scholar
Lund, T. S. & Novikov, E. A. 1993 Parameterization of subgrid-scale stress by the velocity gradient tensor. In CTR Annual Research Briefs, pp. 2743. Stanford University.Google Scholar
Perot, B. & Moin, P. 1996 A new approach to turbulence modelling. In Proceeding of the CTR Summer Program, pp. 3546. Stanford University.Google Scholar
Townsend, A. A. 1961 Equilibrium layers and wall turbulence. J. Fluid Mech. 11, 97120.Google Scholar
Townsend, A. A. 1976 The Structure of Turbulent Shear Flow, 2nd edn. Cambridge Uiversity Press.Google Scholar
Van Atta, C. W. & Wyngaard, J. C. 1975 On higher-order spectra of turbulence. J. Fluid Mech. 72, 673694.CrossRefGoogle Scholar
Verma, M. K. 2004 Statistical theory of magnetohydrodynamic turbulence: recent results. Phys. Rep. 401, 229380.Google Scholar
Wallace, J. M., Eckelmann, H. & Brodkey, R. S. 1972 The wall region in turbulent shear flow. J. Fluid Mech. 64, 3948.Google Scholar
Wu, J., Zhou, Y., Lu, X. & Fan, M. 1999 Turbulent force as a diffusive field with vortical forces. Phys. Fluid 11, 627635.Google Scholar
Wu, J., Zhou, Y. & Wu, J.1996 Reduced stress tensor and dissipation and the transport of Lamb vector. Rep. 96-21. ICASE.Google Scholar