Numerical investigation of near-wall transport and structure formation processes in turbulent Rayleigh-Bénard convection

湍流对流边界层的温度和速度动力学过程对于更详细地确定全球热输运具有重要意义。在本项目中，我们希望通过直接数值模拟的方法来研究湍流瑞利-巴萨姆德对流边界层的动力学和结构形成。因此，我们想改变瑞利数和普朗特数以及圆柱对流单元的长径比，并研究全局输运规律对这些参数的依赖关系。同时，我们希望研究近壁相干结构，它们在边界层中的动力学以及它们对全局输运性质的统计影响。我们的模拟将揭示对流边界层与经典边界层的差异，并解决在高瑞利数时向湍流过渡的开始。

The dynamical processes in the temperature and velocity boundary layers of a turbulent convection flow are of fundamental interest for a more detailed determination of the global heat transport. In the present project, we want to study the dynamics and structure formation in the boundary layers of turbulent Rayleigh-Bénard convection by means of direct numerical simulations. We want to vary therefore the Rayleigh and Prandtl numbers as well as the aspect ratio of the cylindrical convection cell and study the dependence of the global transport laws on these parameters. In parallel we want to investigate the near-wall coherent structures, their dynamics in the boundary layers and their statistical impact on the global transport properties. Our simulations will unravel the differences of the convection boundary layers to the classical boundary layers and resolve the beginning of the transition to turbulence at high Rayleigh numbers.