Experimental Studies on Compressible Vortex Rings and their Interactions with Stationary and Moving Flat Surfaces

涡旋环体现了涡旋运动的各种基本特征。它们紧凑的性质也使它们成为复杂流建模中较简单的构建块的理想选择。不幸的是，尽管它们看起来很简单，但与旋涡环本身的大多数方面有关，包括它们的形成、传播和衰减，在它们的动力学和由可压缩性影响引入的能量学方面，仍有许多未解决的问题。此外，与不可压缩涡环相比，与可压缩涡环相关的流动和相互作用受到的关注很少。本文的目的是对可压缩涡旋环及其与静止和运动平面的相互作用进行系统的实验研究。所提出的工作是新颖的，因为他们的详细研究是有限的，有许多问题未解决的相关流场。由于可压缩涡环及其相互作用与当前非致命武器技术发展、运输、混合和湍流研究、风洞实验、弹丸、导弹和其他细长物体周围的高速气动流动、涡轮机械、气动声学、消声器和炮口制动器设计、大气研究、脉冲爆震发动机、汽车排气流场等密切相关，因此提出的工作也是及时的。这项调查将在曼彻斯特大学的激波管设施中进行，使用一系列先进的实验技术。这项工作分为三个任务。任务1将研究孤立可压缩涡旋环的基本流动物理。任务2将研究可压缩涡旋环与静止和运动平面的相互作用。任务3将研究可压缩涡旋环与反射激波的相互作用。

Vortex rings embody various essential characteristics of vortical motion. Their compact nature also makes them ideal as simpler building blocks in the modelling of complex flows. Unfortunately, despite their apparent simplicity, there are still many unanswered questions related to most aspects of the vortex rings themselves, including their formation, propagation and decay, with more challenging complexities in both their dynamics and energetics introduced by effects of compressibility. Additionally, the flows and interactions associated with compressible vortex rings have received very little attention as compared to those associated with incompressible vortex rings. The present proposal is for a systematic experimental study of compressible vortex rings and their interactions with stationary and moving flat surfaces. The proposed work is novel because their detailed study is limited and there are many questions unanswered associated with these flow fields. The proposed work is also timely because compressible vortex rings and their interactions are highly relevant to current non-lethal-weapon technology development, transport, mixing and turbulence research, wind tunnel experiments, high-speed aerodynamic flows around projectiles, missiles and other slender bodies, turbomachinery, aero-acoustics, suppressors and muzzle brakes design, atmospheric research, pulse detonation engines, automobile exhaust flow fields etc. The investigation will be conducted in the University of Manchester shock tube facility using a range of advanced experimental techniques. The work is divided into three tasks. Task 1 will study the fundamental flow physics of the isolated compressible vortex ring. Task 2 will investigate the compressible vortex ring interaction with stationary and moving flat surfaces. Task 3 will examine the compressible vortex ring interaction with reflected shock waves.