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Turbulent Rayleigh-Benard convection in a bounded vertical layer of size 1 × Γ × 1 (Γ is the aspect ratio that characterizes the layer thickness) is studied by two-dimensional (2D) and quasi-two-dimensional (Q2D) direct numerical simulations (DNS) mainly performed for Rayleigh number Ra = 2.2 · 109 and Prandtl number Pr = 7. The simulation results are verified by comparison with the results of an experimental investigation into the convective flow of water in a rectangular box heated from below with dimensions 250 × d × 250 mm3 (d varied from 15 to 50 mm). It is shown that, even in the framework of a crude model of linear friction used in the Q2D model, consideration of friction on lateral boundaries allows us to get a realistic structure of the turbulent flow with the aspect ratio Γ ≤ 0.1. In addition, the Q2D model correctly describes the dynamics of the large-scale flow and reproduces the experimental power spectral density of velocity fluctuations.
Author(s):
Peter Frick
ICMM - Perm
Russian Federation
Andrey Teymurazov
ICMM - Perm
Russian Federation
Andrey Vasiliev
Perm State National Research University
Russian Federation