Heat transfer and flow structure in centrally-confined 2-D Rayleigh-Bénard convection  

作　　者：Cong Sun Jian-zhao Wu Xiao-hui Meng Cai-xi Liu Wei Xu Yu-hong Dong Quan Zhou 

机构地区：[1]Shanghai Institute of Applied Mathematics and Mechanics,School of Mechanics and Engineering Science,Shanghai Key Laboratory of Mechanics in Energy Engineering,Shanghai University,Shanghai,200072,China [2]China Electrical Equipment Group Research Institute of Science and Technology Co.Ltd.,Shanghai,200072,China

出　　处：《Journal of Hydrodynamics》2024年第4期772-780,共9页水动力学研究与进展B辑（英文版）

基　　金：Project supported by the Natural Science Foundation of China(Grant Nos.11988102,92052201,11825204,12102246 and 12372220).

摘　　要：Through direct numerical simulations,we investigated the flow structure and heat transfer of the centrally confined 2-D Rayleigh-Bénard(RB)convection over the Rayleigh number range 9×10^(5)≤Ra≤10^(9) at a fixed Prandtl number Pr=4.3.It is found that with increasing Ra,the number of convection rolls in the central vertical channel increases from zero to three.When there is no rolls in the vertical channel,the convective flow in central region is significantly influenced by the boundary layer,whereas when the convection rolls is generated in the vertical channel,the convective flows in central regions is free from the boundary layer limitation,and by defining the characteristic length,one obtains the heat transfer scaling law relation in vertical channel,i.e.,Nu_(vc)∼Ra_(vc)^(0.476±0.005),which could be the evidence of“ultimate regime”.

关 键 词：Rayleigh-Benard(RB)turbulence heat transport vertical channel ultimate regime 

分 类 号：O35[理学—流体力学]