Visualisations by LASER topographies and velocity measurements by LDV have allowed the study of the fiow resulting from the illteraction between a circular jet and a cross boundary layer. This type of fiow is dominated by the presence of many complex vortices that come from the recombining of the vorticity created in the injection tube and that created aIong the chamber floor. Visualisations by LASER topographies and velocity measurements by LDV have allowed the study of the fiow resulting from the illteraction between a circular jet and a cross boundary layer. This type of fiow is dominated by the presence of many complex vortices that come from the recombining of the vorticity created in the injection tube and that created a Iong the chamber floor.