中国科学院大学学报2025，Vol.42Issue(6)：738-746,9.DOI:10.7523/j.ucas.2024.020
旋转系统中穿透Rayleigh-Bénard对流的数值模拟
Numerical simulation for penetrative Rayleigh-Bénard convection in a rotating system
摘要
Abstract
The rotating penetrative convection in the fields of Earth science and engineering has attracted extensive attention.Due to the density inversion property of water near 4 ℃,cold water is used as the working fluid in the present paper to study the rotating penetrative Rayleigh-Bénard convection in a vertical annulus.Direct numerical simulation is performed to analyze the convective heat transfer of cold water under various parameter conditions,with the density inversion parameterθm=0.0,0.5,the inverse Rossby number 1/Ro and the Rayleigh number Ra changing in the ranges 0≤1/Ro≤10 and 104≤Ra≤108.The present results show that in the non-rotating cases(i.e.1/Ro=0),the penetrative convection of cold water with θm=0.5 exhibits significant up-down asymmetry,with the top thermal boundary layer thickness δθtop greater than the bottom oneδθbottom·The scaling exponents of the Nusselt number Nu and δθ versus Ra are approximately±0.3.In the rotating cases(i.e.1/Ro＞0),the flow changes with increasing the rotation rate(i.e.1/Ro),leading to the transition of flow regime from thermal plumes to vortex columns at moderate 1/Ro.Particularly noteworthy is that for θm=0.0 both the cold and hot plumes are strong enough to form vortex columns in a certain range of 1/Ro,while the density inversion property at θm=0.5 renders the cold plumes weak so that only hot plumes can be converted into vortex columns.As a result,the augmentation of heat transfer,induced by the formation of vortex columns,for θm=0.5 is not as significant as that for θm=0.0.For the rotating penetrative convection of cold water with θm=0.5,at moderate to high 1/Ro,the thermal boundary layer thickness δθ exhibits a scaling lawδθ～1/Ro12,while the velocity boundary layer thickness δu still follows δu～1/Ro-1/2.关键词
密度倒置/穿透Rayleigh-Bénard对流/旋转系统/数值模拟Key words
density inversion/penetrative Rayleigh-Bénard convection/rotating system/numerical simulation分类
能源科技引用本文复制引用
王崧,曹玉会..旋转系统中穿透Rayleigh-Bénard对流的数值模拟[J].中国科学院大学学报,2025,42(6):738-746,9.基金项目
国家自然科学基金(52176025)资助 （52176025）
