Experimental analysis of the influence of the impinged plate by an impinging jet on the vortex dynamics using PIV

摘要

In this experimental study, we are interested in the flow generated by a plane jet impacting on different plates. To analyse these flows and to compare the evolutions of the various parameters (velocities, turbulence rate, vortex structures, etc.), the PIV technique was used. For example, for a confinement ratio of 4 and a Reynolds number of 4838, a comparison is made between the deviated flows for each of the three plates considered in this study. For the smooth slotted plate, it is noted that the large structures created by the shear between the jet and the driving zone are convected and are organized differently according to the initial dynamics of the flow (Re). Indeed, depending on the configuration, these large structures are either deviated laterally in the parietal flow or pass alternately through the slot. With regard to the solid plates, Kelvin Helmholtz’s structures are always deflected, the parietal flow is more nourished but its vortex dynamics is influenced by the surface state. Indeed, for the smooth solid plate we have large swirl structures whereas for the corrugated plate, we notice the appearance of small vivid and intense vortex structures. A quantitative analysis of these phenomena is conducted in order to study and compare parietal flows.