European Turbulence Conference 2015

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16:30
15 mins

Similarities between 2D and 3D convection for large Prandtl number
Anando Chatterjee, Ambrish Pandey, Mahendra Verma, Biplab Dutta

Session: Geophysical and astrophysical turbulence 2
Session starts: Thursday 27 August, 15:00
Presentation starts: 16:30
Room: Room C

Anando Chatterjee (IIT Kanpur, Kanpur, India)
Ambrish Pandey (IIT Kanpur, Kanpur, India)
Mahendra Verma (IIT Kanpur, Kanpur, India)
Biplab Dutta (IIT Kanpur, Kanpur, India)

Abstract:
Using direct numerical simulations of Rayleigh-B\'enard convection (RBC), we perform a comparative study of the spectra and fluxes of energy and entropy for large and infinite Prandtl numbers in two (2D) and three (3D) dimensions. We observe close similarities between the 2D and 3D RBC, in particular the kinetic energy spectrum $E_u(k) \sim k^{-13/3}$, and the entropy spectrum exhibits a dual branch with a dominant $k^{-2}$ spectrum. We showed that the dominant Fourier modes in the 2D and 3D flows are very close.