权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

View of the reconnection of the vortex line and its acoustic emission

涡线重连及其声发射的视图

基本信息

批准号：
05650186
负责人：
MINOTA Toyoko
金额：
$ 1.41万
依托单位：
Ariake National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05650186/
关键词：
Reconnection of Vortex Line Compressible Vortex Ring Shock-Vortex Interaction Shadowgraph of Vortex Ring Vortex Sound 渦音高速渦輪衝撃波

项目摘要

Optical experimental studies have been performed to understand flowfield and vortex structures in the head on collision and the oblique collision of two compressible vortex rings, and in the vortex ring approaching a plane wall.When the vortex ring comes close to the rigid wall, a strong separation bubble is generated from the wall boundary layr induced by the ring and the following flow and develops the secondary vortex.It is seen in all cases that an inward facing new shock is formed between the cores of two vortices approaching each other.The formation of this shock is the same mechanism in the convergent-divergent nozzle flow.It means that the strong vortex cores act in a way similar to the nozzle.As the two vortex rings approach, the instability with the small-amplitued and short-wavelength develops on the vortex core lines.The wavy vortex core lines begin to wind round at the point of contact.The vortex lines coming into a head-on collision are stretched in the radial direction at the high speed, and expand to a turbulent cloud around the vortex core lines.In the oblique collision, the vortices at the contact points stretches and coil around the vortex line.The anti-parallel vortices are canceled and the vortex lines show the structure of the reconnection.Morphological structures on the process of reconnection of the vortex lines resemble to computed vortex structures.The secondary vortex ring developing from the separation bubble rise from the wall, and get in the interior of the primary vortex from the outside.The sound waves generate in all cases when the vortex cores wind round each other.

本文对两个可压缩涡环的头部碰撞和斜碰撞以及涡环靠近平板壁面时的流场和涡结构进行了光学实验研究，当涡环靠近平板壁面时，环和后续流动诱导壁面边界层产生强烈的分离气泡，并发展出二次涡。从总体上看，在两个相互靠近的涡核之间形成一个向内的新激波的情况下，这种激波的形成与收敛-扩张喷管流中的机制相同，即强涡核的作用方式与喷管相似，随着两个涡环的靠近，小振幅和短振幅的不稳定性，在涡核线上产生了一个波长，在接触点处，波浪形涡核线开始缠绕，涡线进入头部，碰撞时的涡核沿径向高速拉伸，并在涡核线周围扩展成湍流云。在斜碰撞中，接触点处的涡在涡线周围伸展和盘绕，反平行涡被取消，涡线显示了重联的结构。涡线与计算得到的涡结构相似，分离泡发展出的二次涡环从壁面上升，从外部进入一次涡内部，在所有情况下，涡核相互缠绕时都产生声波。