An experiment on jet-wake vortex interaction

The flow field produced by the interaction of two heated jets with the wake vortices of a rectangular wing is investigated in a research-type wind tunnel using an experimental set up producing conditions representative of an aircraft in cruise flight. The flow is characterized using a 3D-LDV system and thermocouples. Different spacing distances between the jets and the wing tips are considered. The temperature of the jets is also varying. In general, velocity and temperature contours reveal that the impact of the jets on the vortex properties remains small. Slight variations in the final vortex positions are observed when the jet/vortex spacing is changed due to slight modifications of the spanwise distribution of the vorticity due to the jets. Also, the statistics of the velocity fluctuations reveal that the jet turbulence promotes vortex meandering, probably through transient growth mechanisms. In most of the cases, the jet plume is wrapped around the vortices without penetrating significantly into the cores. However, when the case jet/vortex spacing becomes small, one observes that the jets are quickly trapped into the vortices where they remain confined afterwards. As for the temperature effect, they are found to be almost negligible.