An experimental study of a vortex ring interacting with an inclined wall

Abstract

An experimental study has been made on the interaction of a vortex ring with a plane solid boundary which is inclined to the axis of the ring. Dye visualizations of the ring during the interaction revealed (i) the formation of bi-helical vortex lines around the circumferential axis of the ring, and (ii) that these vortex lines were constantly being displaced along the circumferential axis on either side of the plane of symmetry and towards the region of the ring furthest away from the wall. Key factors which may be responsible for this phenomenon have been identified and are discussed in this paper.

A cell-centered adaptive projection method for the incompressible Navier–Stokes equations in three dimensions

“…To demonstrate that the algorithm is robust enough to handle more complex problems, we also computed an adaptive solution for a viscous vortex ring merger problem, similar to the ones studied computationally in [2,4,17] and experimentally in [5,18]. The initial conditions are two vortex rings which are angled toward each other by an inclination angle φ from horizontal.…”

Back Matter

“…Smoke is introduced uniformly around the circumference of the tube only, and a thin laser sheet is used to illuminate the flow. (a) Depicts the formation of the shear layer vortices and (b) shows the process of vortex tripling (Lim, 1989). It is suggested that Mode A is an "elliptic" instability of the cores, and Mode B is a "hyperbolic" instability of the braid vorticity.…”

“…The Reynolds number of the flow based on the initial velocity and the diameter of the nozzle is about 600. Note how differential vortex stretching has led to the formation of hi-helical vortex lines (see (c)) which are constantly being displaced along the circumferential axis and towards the region of the ring furthest away from the wall (Lim, 1989).…”

“…The interaction is similar to that shown in the previous figure except that dye was placed on the floor only. The time interval between successive photographs is 1 s. Dashed line in ( d)-(i) indicate the approximate position of the circumferential axis of the primary vortex ring (Lim, 1989).…”

A Particle Method and Adaptive Treecode for Vortex Sheet Motion in Three-Dimensional Flow

“…A number of laboratory experiments have been performed to study the interaction of two vortex rings moving side by side in the same direction [58][59][60][61][62][63]. As time proceeds, the rings are drawn together and they merge into a single ring that later splits apart again into two rings.…”