Turbulent mixing across zero-mean flow density interfaces

该项目将探索在高雷诺数湍流驱动的密度界面上的混合，其中任一层中的平均流动均为零。虽然这是一个经典的问题，但它仍然是一个鲜为人知的问题，现在是时候重新审视并利用最近的实验、数值和理论发展。这项研究将采用DAMTP在过去一年中首创的近瞬时3D速度和密度诊断能力，并将其直接与高分辨率的Direct数值模拟相结合，以探测湍流场的可实现状态。理论发展将借鉴最新的概念，如库普曼模式和非定常周期轨道，以探索湍流的结构和动力学。

This project will explore mixing across a density interface driven by high-Reynolds number turbulent flows in contexts where there is zero mean flow in either layer. While this is a classical problem, it is one that remains poorly understood and it is timely to look afresh and make use of recent experimental, numerical and theoretical developments. The research will employ the near-instantaneous 3D velocity and density diagnostic capability pioneered in DAMTP during the last year, and couple this directly with high-resolution Direct Numerical Simulations to probe realisable states of the turbulent field. Theoretical developments will draw on recent ideas such as Koopman modes and unsteady period orbits to probe the structure and dynamics of the turbulence.