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

涡环体现了涡旋运动的各种基本特征。它们的紧凑特性也使它们成为复杂流动建模中更简单的构建块。不幸的是，尽管涡环表面上看起来很简单，但关于涡环本身的大部分方面，包括它们的形成、传播和衰变，仍然有许多悬而未决的问题，由于可压缩性的影响，它们的动力学和能量学都具有更具挑战性的复杂性。此外，与不可压缩涡环相关的流动和相互作用相比，与可压缩涡环相关的流动和相互作用受到的关注很少。本文对可压缩涡环及其与静止和运动平板的相互作用进行了系统的实验研究。所提出的工作是新颖的，因为他们的详细研究是有限的，而且与这些流场相关的许多问题还没有得到解答。拟议的工作也是及时的，因为可压缩涡环及其相互作用与当前的非致命武器技术发展、运输、混合和湍流研究、风洞实验、绕射弹、导弹和其他细长物体的高速气动流动、涡轮机械、气动声学、抑制器和炮口刹车设计、大气研究、脉冲爆震发动机、汽车排气流场等高度相关。这项工作分为三项任务。任务1将研究孤立可压缩涡环的基本流动物理。任务2将研究可压缩涡环与静止和运动平面的相互作用。任务3将研究可压缩涡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.