The effect of Schmidt Number on Stratified Entrainment
From a review of the literature, including a new theory on vortex persistence, the effect of Schmidt (or Prandtl) number on stratified entrainment is discussed. In contrast to unstratified turbulence, stratified turbulence entrainment depends on diffusive properties of the stratifying agent. Stratification inhibits the large scale motions of the flow which would otherwise dominate entrainment, so that smaller scale processes become important. At sufficiently large Richardson number, the diffusion of solutal (or heat) at small scales determines the entrainment rate. Thus stratification can act as a probe of the turbulence, suppressing normally dominant features to reveal weaker, more subtle effects.
KeywordsPrandtl Number Richardson Number Schmidt Number Entrainment Rate Small Eddy
Unable to display preview. Download preview PDF.
- Turner, J.S. 1973. Buoyancy effects in fluids. Cambridge University Press.Google Scholar
- Cotel, A.J. 1995. Entrainment and Detrainment of a Jet Impinging on a Stratified Interface, Ph.D. thesis, University of Washington.Google Scholar
- Cotel, A.J. and Breidenthal, R.E. 1996. A Model of Stratified Entrainment Using Vortex Persistence. Submitted to Applied Scientific Research.Google Scholar
- Landau, L.D. and Lifshitz, E.M. 1959. Fluid Mechanics. Pergamon Press, 122.Leveque, M.A. 1928. Les lois de la transmission de la chaleur par convection. Ann. Mines, 13: 201-239.Google Scholar
- Fernando, HJ.S. 1987. Turbulent mixing in the presence of a stabilizing buoyancy flux. Proceedings of the Third International Symposium on Stratified Flows, ed. E.J. List and.H. Jirka, Caltech, 447.Google Scholar
- Elias, F. 1930. Der Warmeubergang einer geheizten Platte an stromende Luft. Abhdlg. Aerodyn. Inst. T. H. Aachen, 9; 1929 ZAMM, 9: 434–453; and 10: 1-14.Google Scholar
- Colburn, A.P. 1933. A method of correlating forced convection heat transfer data and a comparison with fluid friction. Trans. Am. Inst. Chem. Eng., 29: 174–210.Google Scholar
- Bejan, A. 1984. Convective Heat Transfer. Wiley: 248–256.Google Scholar