论文标题
边界区域流动以快速旋转的湍流热对流
Boundary zonal flows in rapidly rotating turbulent thermal convection
论文作者
论文摘要
最近，在Zhang等人中。 （2020），发现在较细长的圆柱容器中迅速旋转的动荡雷利 - 贝纳德对流（rbc）中，填充了一个较大的prandtltl-number流体（$ pr \ pr \ pr \ pr \ pr \ pr \ pr \ pr \ pr \ pr \ pr \ pr \ f \ pr \ f \ pr \ f \ lsc），大小循环（lsc coppulation and deffert and deffert and deffert and deffert and deffert and defferct and defferction（lsc），zon（B）以温度，气旋流体运动和流动模式的反气旋漂移（相对于旋转框架）为特征。该BZF的总热量$ pr <1 $的总热量量（$> 60 \％$）的数量不成比例，但对于较大的$ pr $，较大的$ pr $突然减少至$ 35 \％$ $。在这项工作中，我们表明BZF很强大，并且出现在不同$γ$的容器以及$ pr $和$ ra $的容器中迅速旋转的动荡RBC。直接数值模拟，价格为$ 0.1 \ leq pr \ leq 12.3 $，$ 10^7 \ leq ra \ leq ra \ leq 5 \ times10^{9} $，$ 10^{5} \ leq 1/ek \ leq 1/ek \ leq 10^{7} {7} $瑞利号$ ra $和ekman编号$ ek $ as $δ_0/h \simγγ^{0} \ pr^{\ { - 1/4，0 \}} ra^{1/4} ek^{ek^{2/3} $（$ {2/3} $（$ pr^{ - 4/3} ra ek^{5/3} $，其中$ h $是单元高的高度，而$ω$是角旋转速率。 BZF的模式为$γ\ Lessim 1 $和$2γ$的BZF数字为$γ$ = {1,2} $2γ$，独立于$ ra $和$ pr $。 BZF非常让人联想到旋转对流中的壁模式。
Recently, in Zhang et al. (2020), it was found that in rapidly rotating turbulent Rayleigh-Bénard convection (RBC) in slender cylindrical containers (with diameter-to-height aspect ratio $Γ=1/2$) filled with a small-Prandtl-number fluid ($Pr \approx0.8$), the Large Scale Circulation (LSC) is suppressed and a Boundary Zonal Flow (BZF) develops near the sidewall, characterized by a bimodal PDF of the temperature, cyclonic fluid motion, and anticyclonic drift of the flow pattern (with respect to the rotating frame). This BZF carries a disproportionate amount ($>60\%$) of the total heat transport for $Pr < 1$ but decreases rather abruptly for larger $Pr$ to about $35\%$. In this work, we show that the BZF is robust and appears in rapidly rotating turbulent RBC in containers of different $Γ$ and in a broad range of $Pr$ and $Ra$. Direct numerical simulations for $0.1 \leq Pr \leq 12.3$, $10^7 \leq Ra \leq 5\times10^{9}$, $10^{5} \leq 1/Ek \leq 10^{7}$ and $Γ$ = 1/3, 1/2, 3/4, 1 and 2 show that the BZF width $δ_0$ scales with the Rayleigh number $Ra$ and Ekman number $Ek$ as $δ_0/H \sim Γ^{0} \Pr^{\{-1/4, 0\}} Ra^{1/4} Ek^{2/3}$ (${Pr<1, Pr>1}$) and the drift frequency as $ω/Ω\sim Γ^{0} Pr^{-4/3} Ra Ek^{5/3}$, where $H$ is the cell height and $Ω$ the angular rotation rate. The mode number of the BZF is 1 for $Γ\lesssim 1$ and $2 Γ$ for $Γ$ = {1,2} independent of $Ra$ and $Pr$. The BZF is quite reminiscent of wall mode states in rotating convection.
