Investigation of the dynamics of large eddies in the near zone of an axisymmetric free jet in the case with local pulsed injection in the coaxial and transverse directions

Optical diagnostics of the three-dimensional structure of large eddies in the near zone of a turbulent jet (at Re = 5000) exhausting from a round nozzle is performed in the case with coaxial periodic disturbances of the flow through annular slots at the nozzle edge and through holes in the internal surface of the nozzle in the transverse direction. The external action leads to rapid turbulization of the flow near the nozzle edge due to generation of large extended toroidal vortices in the case of coaxial disturbances and due to significant reconstruction of the flow with rapid disintegration of the jet core in the case of transverse disturbances.