Superstructures and turbulent heat and momentum transport in inclined low-Prandtl-number convection

该项目致力于研究低普朗特数流体中倾斜湍流热对流中发展的超结构的起源和动力学。这些超结构是跟随大规模流体循环的热羽流的集群。在该项目中，将开发或改进识别、提取和分析上层建筑的几何和物理特性及其时间演变的算法。超结构将从我们的直接数值模拟中产生的流场中提取。这里的重点将是低普朗特数的流体，如在液体金属，和细长的对流细胞，在一个倾斜的热对流细胞的浮力和剪切的有利组合可以显着提高传热相比，经典的瑞利-贝纳德对流没有任何细胞倾斜。特别是，我们将调查的贡献的超级结构的全球热量和动量输运系统中，这是表示，分别由努塞尔数和雷诺数。此外，控制参数，如瑞利数，普朗特数，对流细胞的长度比和倾斜角度的上层结构动力学的影响，将被研究。最后，局部热输运（努塞尔数）和瞬时形式的上层建筑之间的关系将进行调查。

The project is devoted to the investigation of the origin and dynamics of the superstructures that develop in inclined turbulent thermal convection in low Prandtl-number fluids. These superstructures are clusters of the thermal plumes that follow the large-scale circulation of the fluid. Within the project, algorithms to identify, extract and analyze the geometrical and physical properties of the superstructures and their temporal evolution are to be developed or advanced. The superstructures will be extracted from the flow fields that will be generated in our direct numerical simulations. The focus here will be on low Prandtl-number fluids, like in liquid metals, and on slender convection cells, where a favourable combination of buoyancy and shear in a tilted thermal convection cell can significantly enhance the heat transfer, compared to the classical Rayleigh-Benard convection without any cell tilt. In particular, we will investigate the contribution of the superstructures to the global heat and momentum transport in the system, which are expressed, respectively, by the Nusselt and Reynolds numbers. Furthermore, the influence on the superstructures dynamics of the control parameters, such as the Rayleigh number, Prandtl number, convection cell length ratios and the angle of inclination, will be studied. Finally, the relationship between the local heat transport (Nusselt number) and the instantaneous form of the superstructure will be investigated.