An Experimental Study of Flow Reversals in Quasi-2D Rayleigh-Benard Convection
ORAL
Abstract
We present an experimental study of flow reversals of the large-scale circulation in turbulent Rayleigh-Benard convection in a quasi-2D rectangular convection cell with aspect ratio 0.84. Using water as the convecting fluid the range of Rayleigh number varied from around 10$^{8}$ to 10$^{10}$ and the Prandtl number is around 5.8 in the experiment. From local temperature measurements it is found that, contrary to the 3D case, the rate of flow reversals has a strong dependence on the Rayleigh number, i.e. it decreases with increasing Ra. By using thermal plumes as tracer particles, we use shadowgraphs to obtain the velocity field of plume clusters. The results suggest the role played by the plumes in the reversal process.
*Work supported by the Research Grants Council of Hong Kong SAR (Project Nos. CUHK 403807).
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Authors
Rui Ni
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Tak-Shing Chan
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Sheng-Qi Zhou
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Heng-Dong Xi
Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong, China
Ke-Qing Xia
Department of Physics, The Chinese University of Hong Kong, Hong Kong
Kazu Sugiyama
Department of Science and Technology, University of Twente, The Netherlands
Enrico Calzavarini
Department of Science and Technology, University of Twente, The Netherlands
Chao Sun
Department of Science and Technology, University of Twente, The Netherlands
Detlef Lohse
Department of Science and Technology, University of Twente, The Netherlands
