Experimental investigations of the influence of axial jets on 2- and 4-vortex systems

The effects of jets on wake vortices were investigated experimentally in a towing tank. Considered are two cases of 4-vortex systems consisting of two counter-rotating vortex pairs. For a comparisons, the corresponding 2-vortex system is also considered, too. The used vortex generator consisting of one or two rectangular wings was equipped with two pressurized water jet nozzles. Two different jet strengths were used, resulting in parameter valuess of R (ratio between jet thrust and vortex strength) of 0.2 and 0.74. Cross-plane velocity fields were determined by means of Stereo-PIV. The jet/vortex interactions are discussed, as well as the influence of the jets on the occurrence of an interaction between inner and outer vortices in the near far field, which is presumed to lead to a more rapid decay of the wing vortices