Salinity transfer in double diffusive convection bounded by two parallel plates

ORAL

Abstract

The double diffusive convection (DDC) is the convection flow with the fluid density affected by two different components. In this study we numerically investigate DDC between two parallel plates with no-slip boundary conditions. The top plate has higher salinity and temperature than the lower one. Thus the flow is driven by the salinity difference and stabilised by the temperature difference. Our simulations are compared with the experiments by Hage and Tilgner (\emph{Phys. Fluids}, vol.~22, 076603, 2010) for several sets of parameters. Reasonable agreement is achieved for the salinity flux and its dependence on the salinity Rayleigh number. For all parameters considered, salt fingers emerge and extend through the entire domain height. The thermal Rayleigh number shows minor influence on the salinity flux although it does affect the Reynolds number. We apply the Grossmann-Lohse theory for Rayleigh-B\'{e}nard flow to the current problem without introducing any new coefficients. The theory successfully predicts the salinity flux with respect to the scaling for both the numerical and experimental results.

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Authors

  • Yantao Yang

    Physics of Fluids Group, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands

  • Erwin van der Poel

    Physics of Fluids Group, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands, PoF Univ. of Twente, University of Twente

  • Rodolfo Ostilla Monico

    Physics of Fluids Group, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands, Physics of Fluids, Mesa+ Institute, University of Twente, P.O. Box 217, 7500 AE Enschede

  • Chao Sun

    University of Twente, Physics of Fluids Group, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands, Physics of Fluids, Faculty of Science \& Technology, University of Twente, The Netherlands

  • Roberto Verzicco

    Dipartimento di Ingegneria Industriale, University of Rome ``Tor Vergata'', Via del Politecnico 1, Roma 00133, Italy, DII, University of Roma Tor Vergata, Dipartimento di Ingegneria Meccanica, University of Rome ``Tor Vergata,'' Via del Politecnico 1, Roma 00133, Italy, Universita degli Studi di Roma Tor Vergata, Universita di Roma ``Tor Vergata''

  • Siegfried Grossmann

    Fachbereich Physik, Philipps-Universitat Marburg, Renthof 6, D-35032 Marburg, Germany, Department of Physics, University of Marburg, Renthof 6, D-35032 Marburg, Germany

  • Detlef Lohse

    University of Twente, Physics of Fluids Group, Faculty of Science and Technology, University of Twente, 7500 AE Enschede, The Netherlands, PoF Univ. of Twente, Physics of Fluids, Mesa+ Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, Physics of Fluids, Faculty of Science \& Technology, University of Twente, The Netherlands, Physics of Fluids, University of Twente, Univ of Twente