Experimental study of instabilities appearing in a round jet at a low Reynolds number

The objective of this work is to study the Kelvin-Helmholtz instabilities appearing in a monophase fluid jet evolving at low Reynolds numbers. The study concerns at the near region of the nozzle exit (the transition zone), and it's localized on the evolution in the space and in the time of aerodynamic instabilities specific to this type of out-flow. In this experimental survey, the instabilities are described qualitatively then quantitatively by technique of tomography by laser plan associated to operators of image processing. Interest is in particular in the study of the structures generated by the instability of the jets as well as the determination of their characteristic parameters. (author)