论文标题
限制湍流水平对流的机制。第一部分：中级和低prandtl号码
Limiting regimes of turbulent horizontal convection. Part I: Intermediate and low Prandtl numbers
论文作者
论文摘要
我们报告了使用中间至低prandtl数字处的直接数值模拟在水平对流（HC）中存在两个新的限制湍流方案。沿水平表面的水平梯度驱动的流量垂直于重力加速度，显示出向羽流和核心中的湍流过渡，从而改变了热和动量传输的速率。这些过渡设定了一系列缩放定律，将Shishkina，Grossmann＆Lohse（SGL）理论与Hughes，Griffiths＆Mullarney（HGM）制度融合了理论论点。这些结果将HGM模型嵌入了SGL理论中，同意并扩展了高瑞利数字的水平对流制度图。特别是，我们表明，HC和Rayleigh-Bénard在低普罗兰德数字上具有相似的湍流特征，其中首次显示HC由其核心动力学和湍流边界层统治。这种新方案证实，相对于先前报道的高瑞利数字，完全湍流的HC增强了热量和动量的运输。这项工作提供了有关水平对流对地球物理流的适用性的新见解，例如在大气中发现的倒流，海洋和地球内部核心附近的流动。
We report the existence of two new limiting turbulent regimes in horizontal convection (HC) using direct numerical simulations at intermediate to low Prandtl numbers. The flow driven by a horizontal gradient along a horizontal surface, perpendicular to the acceleration of gravity is shown to transition to turbulence in the plume and the core, modifying the rate of heat and momentum transport. These transitions set a sequence of scaling laws blending the theoretical arguments from both the Shishkina, Grossmann & Lohse (SGL) theory with the Hughes, Griffiths & Mullarney (HGM) regime. These results embed the HGM model in the SGL theory, agree, and extend the known regime diagram of horizontal convection at high Rayleigh numbers. In particular, we show that HC and Rayleigh-Bénard share similar turbulent characteristics at low-Prandtl numbers, where HC is shown for the first time to be ruled by its core dynamics and turbulent boundary layers. This new scenario confirms that fully turbulent HC enhances the transport of heat and momentum with respect to previously reported regimes at high Rayleigh numbers. This work provides new insights on the applicability of horizontal convection for geophysical flows such as overturning circulations found in the atmosphere, the oceans, and flows near the earth's inner core.
