The Python Link in DynamicStudio, which was introduced earlier this year, has been applied to gain more insight into the interaction of ring vortices in an accelerating water jet, measured by Tomographic PTV. This work was presented at the European Fluid Dynamics Conference in Aachen by Pietro Sperotto.
An accelerating jet is created by a pulsed pump connected to a nozzle. The water is initially quiescent. When the pulsed pump is turned on, it creates an accelerating jet with vortex rings. Data from the experiment have been acquired with a tomographic PTV system with 4 FlowSense FCX 5M-124 cameras and an LED array, in a volume of 205 x 125 x 115 mm³. Results of this were presented at the International Symposium of PIV 2023 in San Diego.
The first vortex ring is slow and has a large diameter. As the jet accelerates, the next vortex ring is smaller and moves faster, so it catches up with the first one and eventually passes through it, picking up vorticity on the way. Finally, the rings merge. The Python Link greatly helped understand the phenomenon by separating the vortex rings before their interaction by their vorticity magnitude or the Q-criterion. Synthetic particles are injected into each vortex ring and are advected with the flow, using the Eulerian velocity field. Finally, their tracks are fed back as a separate tracking data set into DynamicStudio for visualization.
Download application note
Categories
