Speaker
Description
Rayleigh-Bénard convection [1-2], i.e. heat and momentum transport driven by thermally induced buoyancy force, occurs between two horizontal parallel plates which are heated from the bottom and cooled from the top. It is deemed as a paradigmatic in the study of thermal fluid flow. In the past decades, magnetohydrodynamic RB convection [3] and radiative RB convection [4] have received a great deal of attention. A review paper about RB convection with magnetic field or radiation can be found in [5]. However, few research focus on investigating the combined effects of thermal radiation and magnetic field, namely, radiative magnetohydrodynamic RB convection [6]. Therefore, in present work, we perform numerical simulations to study the heat transfer and fluid motion in a square cavity filled with electrically conducting and radiatively participating molten salts at for under different Hartmann number Ha and Planck number Pl. Here, Ha denotes the ratio of the magnetic force over the viscous force and Pl represent the ratio of the conductive heat flux over the radiative heat flux. The magnetic field is applied from the bottom wall. The flow field and temperature field are obtained by solving Navier-Stokes equations and heat transfer equation using collocation spectral method. As for the radiation field, we adopt discrete ordinate method to solve radiative transfer equation. The numerical results show that, thermal radiation at has little effect on convection in the absence of magnetic field. However, when the magnetic field is involved, it shows an obvious difference between the case with and without radiation. The global convective heat transfer at is lower than that without radiation at a fixed Ha. Besides, we noticed that Pl has positive or negative influence on overall convective heat transfer when and 50, while the positive effect disappears at and 150, indicating the suppression of magnetic field is beyond the improvement of thermal radiation.
Acknowledgements
This work was supported by the Deutsche Forschungsgemeinschaft (467227170), the Natural Science Foundation of China (No. 51976021), and the China Scholarship Council (No. 202206060015).
References
[1] H. Bénard, Annales de Chimie et de Physique, 1901, 23: 62-144.
[2] L. Rayleigh, Philosophical Magazine, 1916, 32: 529-546.
[3] S. Chandrasekhar, New York: Dover publications INC, 1981.
[4] R.M. Goody, Journal of Fluid Mechanics, 1956, 1: 424-435.
[5] J.J. Song, P.X. Li, L. Chen, et al. International Communications in Heat and Mass Transfer, 2023, 144: 106784.
[6] C.G.N. Ketchate, P.T. Kapen, D. Fokwa, et al. Chinese Journal of Physics, 2022, 79: 514-530.
