Hostname: page-component-84b7d79bbc-rnpqb Total loading time: 0 Render date: 2024-07-26T07:51:23.389Z Has data issue: false hasContentIssue false

Numerical study of the return of axisymmetric turbulence to isotropy

Published online by Cambridge University Press:  19 April 2006

U. Schumann
Affiliation:
Institut für Reaktorentwicklung, Kernforschungszentrum Karlsruhe, 7500 Karlsruhe, Postfach 3640, West Germany
G. S. Patterson
Affiliation:
National Center for Atmospheric Research, Boulder, Colorado 80307

Abstract

The spectral method of Orszag & Patterson (1972a, b) is used here to study pressure and velocity fluctuations in axisymmetric, homogeneous, incompressible, decaying turbulence at Reynolds numbers Reλ [lsim ] 40. In real space 323 points are treated. The return to isotropy is simulated for several different sets of anisotropic Gaussian initial conditions. All contributions to the spectral energy balance for the different velocity components are shown as a function of time and wavenumber. The return to isotropy is effected by the pressure-strain correlation. The rate of return is larger at high than at low wavenumbers. The inertial energy transfer tends to create anisotropy at high wavenumbers. This explains the overrelaxation found by Herring (1974). The pressure and the inertial energy transfer are zero initially as the triple correlations are zero for the Gaussian initial values. The two transfer terms are independent of each other but vary with the same characteristic time scale. The pressure-strain correlation becomes small for extremely large anisotropies. This can be explained kinematically. Rotta's (1951) model is approximately valid if the anisotropy is small and if the time scale of the mean flow is much larger than 0·2 Lf/v, which is the time scale of the triple correlations (Lf = integral length scale, v = root-mean-square velocity). The value of Rotta's constant is less dependent upon the Reynolds number if the pressure-strain correlation is scaled by v3/Lf rather than by the dissipation. Lumley & Khajeh-Nouri's (1974) model can be used to account for the influence of large anisotropies. The effect of strain is studied by splitting the total flow field into large- and fine-scale motion. The empirical model of Naot, Shavit & Wolfshtein (1970) has been confirmed in this respect.

Type
Research Article
Copyright
© 1978 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Batchelor, G. K. 1946 The theory of axisymmetric turbulence. Proc. Roy. Soc. A 186, 480502.Google Scholar
Batchelor, G. K. 1959 The Theory of Homogeneous Turbulence. Cambridge University Press.
Champagne, F. H., Harris, V. G. & Corrsin, S. 1970 Experiments on nearly homogeneous turbulent shear flow. J. Fluid Mech. 41, 81139.Google Scholar
Daly, B. J. 1974 A numerical study of turbulence transitions in convective flow. J. Fluid Mech. 64, 129165.Google Scholar
Deardorff, J. W. 1974 Three-dimensional numerical study of turbulence in an entraining mixed layer. Boundary-Layer Met. 7, 199226.Google Scholar
Donaldson, C. Dup. 1972 Calculation of turbulent shear flows for atmospheric and vortex motions. A.I.A.A. J. 10, 412.Google Scholar
Elliot, J. A. 1972 Microscale pressure fluctuations measured within the lower atmospheric boundary layer. J. Fluid Mech. 53, 351383.Google Scholar
Hanjalić, K. & Launder, B. E. 1972 A Reynolds stress model of turbulence and its application to thin shear flows. J. Fluid Mech. 52, 609638.Google Scholar
Herring, J. R. 1974 Approach of axisymmetric turbulence to isotropy. Phys. Fluids 17, 859872 (and corrigendum Phys. Fluids, 19 (1976), 177).Google Scholar
Kraichnan, R. H. 1956 Pressure field within homogeneous anisotropic turbulence. J. Acoust. Soc. Am. 28, 6472.Google Scholar
Lee, T. D. 1952 On some statistical properties of hydrodynamical and magneto-hydrodynamical fields. J. Appl. Math. 10, 6974.Google Scholar
Lumley, J. L. & Khajeh-Nouri, B. 1974 Computational modelling of turbulent transport. Adv. Geophys. A 18, 169192.Google Scholar
Naot, D., Shavit, A. & Wolfshtein, M. 1970 Interactions between components of the turbulent velocity correlation tensor due to pressure fluctuations. Israel J. Tech. 8, 259269.Google Scholar
Orszag, S. A. 1969 Numerical methods for the simulation of turbulence. Phys. Fluids Suppl. 12, II 250–257.Google Scholar
Orszag, S. A. & Patterson, G. S. 1972a Numerical simulation of turbulence. In Statistical Models and Turbulence, pp. 127147. Springer.
Orszag, S. A. & Patterson, G. S. 1972b Numerical simulation of three-dimensional homogeneous isotropic turbulence. Phys. Rev. Lett. 28, 7679.Google Scholar
Reynolds, W. C. 1974 Computation of turbulent flows. A.I.A.A. Paper no. 74–556.Google Scholar
Reynolds, W. C. 1976 Computation of turbulent flows. Ann. Rev. Fluid Mech. 8, 183208.Google Scholar
Rodi, W. 1972 The prediction of free turbulent boundary layers by use of a two-equation model of turbulence. Ph.D. thesis, Mech. Engng Dept., Imperial College, London.
Rotta, J. 1951 Statistische Theorie nichthomogener Turbulenz. Z. Phys. 129, 547572.Google Scholar
Schumann, U. 1975 Numerical results for the pressure-strain correlation in channel flows. Rep. KFK-Ext 8/75-7.Google Scholar
Schumann, U. 1976 Numerical simulation of the transition from three- to two-dimensional turbulence under a uniform magnetic field. J. Fluid Mech. 74, 3158.Google Scholar
Schumann, U. & Herring, J. R. 1976 Axisymmetric homogeneous turbulence: a comparison of direct spectral simulations with the direct-interaction approximation. J. Fluid Mech. 76, 755782.Google Scholar
Schumann, U. & Patterson, G. S. 1978 Numerical study of pressure and velocity fluctuations in nearly isotropic turbulence. J. Fluid Mech. 88, 685709.Google Scholar
Shir, C. C. 1973 A preliminary numerical study of atmospheric turbulent flows in the idealized planetary boundary layer. J. Atmos. Sci. 30, 13271339.Google Scholar
Tucker, H. J. & Reynolds, A. J. 1968 The distortion of turbulence by irrotational plane strain. J. Fluid Mech. 32, 657673.Google Scholar
Uberoi, M. S. 1953 Quadruple velocity correlations and pressure fluctuations in isotropic turbulence. J. Aero. Sci. 20, 197204.Google Scholar