Structure Formation Through Coriolis Effects in Rotating Fluid Flows 1=Engineering 2=Fluid Dynamics and Aerodynamics

大气和海洋中的大规模地球物理流动，以及旋转机械中的流动，都受到科氏力对流动液体的作用所产生的独特影响。科里奥利力，由于背景系统旋转，导致许多流动现象，往往是高度反直觉的人不熟悉旋转流体的理论。例子包括泰勒-普罗德曼定理，泰勒列，二维湍流及其令人惊讶的逆能量级联，其中有序是从湍流无序中发展出来的，沿着等压线流动，而不是垂直于这些和惯性波。已有理论公式可以预测这些现象的各个方面。然而，在许多情况下，促进结构形成的物理机制，例如无序和其他现象，仍然是一个激烈争论的问题。布思先生将在我们的旋转转台设施（高6米，直径1.5米）上使用大型水槽进行实验研究，并使用最先进的现代测量技术，例如粒子图像测速（PIV），研究泰勒柱的形成等影响和相关现象。特别是，他将研究，例如，科里奥利效应对射流和喷流的流动动力学。这些代表了在自然环境和应用工程环境中遇到的两种通用流结构的例子。这项研究的目的是阐明当这些结构被科里奥利效应改变时，控制其流动动力学的潜在物理过程。我们在工程学院独特的实验室设施可以进行目前在其他地方无法进行的实验。根据研究的实验部分的进展，可以对所研究的某些方面进行并发计算模拟。作为该项目的一部分，我们还计划与旋转流动学科领域的两位主要理论家（剑桥大学工程系Peter A . Davidson教授和考文垂大学流体和复杂系统学院研究中心Alban Potherat教授）密切合作。

Large-scale geophysical flows in the atmosphere and the oceans, as well as flows in rotating machinery, are subject to unique effects arising from the action of the Coriolis force on the flowing liquid. Coriolis forces, due to background system rotation, result in many flow phenomena that are often highly counter intuitive to anyone not familiar with the theory of rotating fluids. Examples include the Taylor-Proudman theorem, Taylor columns, two-dimensional turbulence with its surprising inverse energy cascade where order develops out of turbulent disorder, flow along isobars instead of perpendicular to these and inertial waves. Theoretical formulations exist that predict aspects of these phenomena. However, in many cases the physical mechanism that does facilitate, for instance, structure formation out of disorder and other phenomena, are still a matter of intense debate. Mr Booth will conduct an experimental study using the large-scale tank on our rotating-turntable facility (height 6 metres, diameter 1.5 metre) and study effects such as the formation of Taylor columns and related phenomena using state-of-the-art modern measurement technologies, e.g. Particle Image Velocimetry (PIV). In particular, he will study, for instance, Coriolis effects on the flow dynamics of jets and puffs. These represent examples of two generic flow structures encountered in the natural environment and in applied engineering contexts. The goal of the research is to shed light on the underlying physical process governing the flow dynamics of these structures when modified by Coriolis effects. Our unique laboratory facility at the School of Engineering enables experiments that are currently not possible elsewhere. Depending on the progress of the experimental part of the study, there is scope to perform concurrent computational simulations of some of the aspects investigated. As part of the project, we moreover plan to work in close collaboration with two of the leading theoreticians in the subject area of rotating flows (Prof. Peter A Davidson, University of Cambridge, Department of Engineering and Prof. Alban Potherat, Coventry University, Faculty Research Centre in Fluid and Complex Systems).