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On the scaling of shear-driven entrainment: a DNS study

Published online by Cambridge University Press:  30 August 2013

Harm J. J. Jonker*
Affiliation:
Department Geoscience and Remote Sensing, Delft University, PO Box 5048, 2600 GA Delft, The Netherlands
Maarten van Reeuwijk
Affiliation:
Department of Civil and Environmental Engineering, Imperial College, London SW7 2AZ, UK
Peter P. Sullivan
Affiliation:
National Center for Atmospheric Research, Boulder, CO 80305, USA
Edward G. Patton
Affiliation:
National Center for Atmospheric Research, Boulder, CO 80305, USA
*
Email address for correspondence: [email protected]

Abstract

The deepening of a shear-driven turbulent layer penetrating into a stably stratified quiescent layer is studied using direct numerical simulation (DNS). The simulation design mimics the classical laboratory experiments by Kato & Phillips (J. Fluid Mech., vol. 37, 1969, pp. 643–655) in that it starts with linear stratification and applies a constant shear stress at the lower boundary, but avoids sidewall and rotation effects inherent in the original experiment. It is found that the layers universally deepen as a function of the square root of time, independent of the initial stratification and the Reynolds number of the simulations, provided that the Reynolds number is large enough. Consistent with this finding, the dimensionless entrainment velocity varies with the bulk Richardson number as $R{i}^{- 1/ 2} $. In addition, it is observed that all cases evolve in a self-similar fashion. A self-similarity analysis of the conservation equations shows that only a square root growth law is consistent with self-similar behaviour.

Type
Papers
Copyright
©2013 Cambridge University Press 

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References

Beare, R. J., Macvean, M. K., Holtslag, A. A. M., Cuxart, J., Esau, I., Golaz, J.-C., Jimenez, M. A., Khairoutdinov, M., Kosovic, B., Lewellen, D., Lund, T. S., Lundquist, J. K., McCabe, A., Moene, A. F., Noh, Y., Raasch, S. & Sullivan, P. 2006 An intercomparison of large-eddy simulations of the stable boundary layer. Boundary-Layer Meteorol. 118 (2), 247272.Google Scholar
Conzemius, R. J. & Fedorovich, E. 2006 Dynamics of sheared convective boundary layer entrainment. Part II: evaluation of bulk model predictions of entrainment flux. J. Atmos. Sci. 63, 11791199.CrossRefGoogle Scholar
Deardorff, J. W. & Willis, G. E. 1982 Dependence of mixed-layer entrainment on shear stress and velocity jump. J. Fluid Mech. 115, 123149.CrossRefGoogle Scholar
Deardorff, J. W. & Yoon, S.-C. 1984 On the use of an annulus to study mixed-layer entrainment. J. Fluid Mech. 142, 97120.Google Scholar
Fernando, H. J. S. 1991 Turbulent mixing in stratified fluids. Annu. Rev. Fluid Mech. 23, 455493.Google Scholar
Galperin, B., Kantha, L. H., Hassid, S. & Rosati, A. 1988 A quasi-equilibrium turbulent energy model for geophysical flows. J. Atmos. Sci. 45, 5562.Google Scholar
Jones, I. S. F. & Mulhearn, P. J. 1983 The influence of external turbulence on sheared interfaces. Geophys. Astrophys. Fluid Dyn. 24, 4962.CrossRefGoogle Scholar
Kantha, L. H., Phillips, O. M. & Azad, R. S. 1977 On turbulent entrainment at a stable density interface. J. Fluid Mech. 79, 753768.Google Scholar
Kato, H. & Phillips, O. M. 1969 On the penetration of a turbulent layer into stratified fluid. J. Fluid Mech. 37 (04), 643655.Google Scholar
Kundu, P. K. K. 1981 Self-similarity in stress-driven entrainment experiments. J. Geophys. Res. 86 (C3), 19791988.CrossRefGoogle Scholar
Large, W. G., McWilliams, J. C. & Doney, S. C. 1994 Oceanic vertical mixing: a review and a model with a non-local boundary layer parameterization. Rev. Geophys. 32 (4), 363403.Google Scholar
Ligniéres, F., Califano, F. & Mangeney, A. 1998 Stress-driven mixed layer in a stably stratified fluid. Geophys. Astrophys. Fluid Dyn. 88, 81113.CrossRefGoogle Scholar
Mellor, G. L. & Durbin, P. A. 1975 The structure and dynamics of the ocean surface mixed layer. J. Phys. Oceanogr. 5, 718728.Google Scholar
Nieuwstadt, F. T. M. 1984 The turbulent structure of the stable, nocturnal boundary layer. J. Atmos. Sci. 41 (14), 22022216.Google Scholar
Pollard, R. T., Rhines, P. B. & Thompson, R. O. R. Y. 1973 The deepening of the wind-mixed layer. Geophys. Fluid. Dyn. 3, 381404.CrossRefGoogle Scholar
Price, J. F. 1979 On the scaling of stress-driven entrainment experiments. J. Fluid Mech. 90, 509529.CrossRefGoogle Scholar
Price, J. F. 1981 Upper ocean response to a hurricane. J. Phys. Oceanogr. 11 (4), 153175.2.0.CO;2>CrossRefGoogle Scholar
van Reeuwijk, M. 2007 Direct simulation and regularization modelling of turbulent thermal convection. PhD thesis, Delft University of Technology.Google Scholar
van Reeuwijk, M., Jonker, H. J. J. & Hanjalić, K. 2008 Wind and boundary layers in Rayleigh–Bénard convection. I. Analysis and modelling. Phys. Rev. E 77, 036311.CrossRefGoogle Scholar
Scranton, D. R. & Lindberg, W. R. 1983 An experimental study of entraining, stressdriven, stratified flow in an annulus. Phys. Fluids 26, 11981205.Google Scholar
Stull, 1998 An Introduction to Boundary Layer Meteorology. Kluwer.Google Scholar
Sullivan, P. P., Moeng, C.-H., Stevens, B., Lenschow, D. H. & Major, S. D. 1998 Structure of the entrainment zone capping the convective atmospheric boundary layer. J. Atmos. Sci. 55, 30423064.Google Scholar
Tennekes, H. 1973 A model for the dynamics of the inversion above a convective boundary layer. J. Atmos. Sci. 30 (4), 558566.Google Scholar
Thompson, R. O. R. Y. 1979 A re-examination of the entrainment process in some laboratory flows. Dyn. Atmos. Oceans 4, 4555.Google Scholar
Thorpe, S. A. 2005 The Turbulent Ocean. Cambridge University Press.CrossRefGoogle Scholar
Troen, I. & Mahrt, L. 1986 A simple model of the atmospheric boundary layer; sensitivity to surface evapouration. Boundary-Layer Meteorol. 37, 129148.Google Scholar
Verstappen, R. W. C. P. & Veldman, A. E. P. 2003 Symmetry-preserving discretization of turbulent flow. J. Comput. Phys. 187 (1), 343368.Google Scholar