Turbulent convection in confined and extended domains

ORAL

Abstract

To understand turbulent convection at very high Rayleigh numbers, direct numerical simulations in slender cells are an option. However, the effects of horizontal confinement on the flow properties need to be assessed. We explore the properties of the flow in a slender cylindrical cell of aspect ratio 0.1 for a wide range of Prandtl numbers and compare them with those in an apparatus of aspect ratio 25. We observe similarities in many flow properties — such as the root mean square fluctuations of temperature and velocity, probability distributions of the temperature fluctuation and the kinetic energy dissipation rate — between the confined and extended convection domains. In addition, we estimate the turbulent Prandtl number and find that it varies very similarly with the molecular Prandtl number in both domains.

*This work was partially supported by EPSRC grant no EP/R014604/1. The authors gratefully acknowledge Shaheen II of King Abdullah University of Science and Technology, Saudi Arabia (under Project No. k1491), as well as Dalma and Jubail clusters at NYU Abu Dhabi for providing computational resources via the Center for Space Science (grant G1502).

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Publication: A. Pandey, D. Krasnov, J. Schumacher, R. Samtaney, and K. R. Sreenivasan, Similar characteristics of convective turbulence in confined and extended domains, Physica D, submitted (2022).

Presenters

  • Joerg Schumacher

    • TU Ilmenau

Authors

  • Ambrish Pandey

    • New York University Abu Dhabi

  • Dmitry Krasnov

    • Institut für Thermo-und Fluiddynamik, Technische Universität Ilmenau, P.O. Box 100565, D-98684 Ilmenau, Germany
    • TU Ilmenau

  • Joerg Schumacher

    • TU Ilmenau

  • Ravi Samtaney

    • King Abdullah Univ of Sci & Tech (KAUST)

  • Katepalli R Sreenivasan

    • New York U.
    • New York University (NYU)
    • NYU, New York, USA
    • Tandon School of Engineering, Courant Institute of Mathematical Sciences, Department of Physics, New York University, New York
    • New York University
    • Department of Mechanical and Aerospace Engineering, Department of Physics and the Courant Institute of Mathematical Sciences, New York University, New York, USA