On The Vortical Developments of Low-Speed Jets

摘要

The vortical structure development experimentally of low speed jetswith different aspect ratio is well studied in this paper. The improved smokeflow visualization method is the main experimental method and twodifferent aspect ratio nozzles are adopted. The side- and front-view near thejet exit are utilized simultaneously in smoke flow visualization experiment.Results not only confirm the development of vortex ring of rectangular jet.But also indicate this evolution has strong relationship between 2D and 3Dvortical structures. Present work also reveals the external excitationobviously excites the flow structure of jets and makes the structures moreorganized. The relationship between vortical spatial evolution and spreadingproperties are also correspondence.