Skip to main content
Article
Scaling and parameterization of stratified homogeneous turbulent shear flow
Journal of Fluid Mechanics (2000)
  • Lucinda H. Shih, Stanford University
  • Jeffrey R. Koseff, Stanford University
  • Joel H. Ferziger, Stanford University
  • Chris R. Rehmann, University of Illinois at Urbana-Champaign
Abstract
Homogeneous sheared stratified turbulence was simulated using a DNS code. The initial turbulent Reynolds numbers (Re) were 22, 44, and 89, and the initial dimensionless shear rate (S*) varied from 2 to 16. We found (similarly to Rogers (1986) for unstratified flows) the final value of S* at high Re to be [similar] 11, independent of initial S*. The final S* varies at low Re, in agreement with Jacobitz et al. (1997). At low Re, the stationary Richardson number (Ris) depends on both Re and S*, but at higher Re, it varies only with Re. A scaling based on the turbulent kinetic energy equation which suggests this result employs instantaneous rather than initial values of flow parameters. At high Re the dissipation increases with applied shear, allowing a constant final S*. The increased dissipation occurs primarily at high wavenumbers due to the stretching of eddies by stronger shear. For the high-Re stationary flows, the turbulent Froude number (Frt) is a constant independent of S*. An Frt-based scaling predicts the final value of S* well over a range of Re. Therefore Frt is a more appropriate parameter for describing the state of developed stratified turbulence than the gradient Richardson number.
Publication Date
June, 2000
Publisher Statement
Copyright 2000 Cambridge University Press
Citation Information
Lucinda H. Shih, Jeffrey R. Koseff, Joel H. Ferziger and Chris R. Rehmann. "Scaling and parameterization of stratified homogeneous turbulent shear flow" Journal of Fluid Mechanics Vol. 412 (2000)
Available at: http://works.bepress.com/chris_rehmann/4/