Crossflow Interactions of Inclined Fluidic Oscillator Jets

Phase-locked stereoscopic particle image velocimetry data were acquired to characterize the flow interactions produced by fluidic oscillator jets ejecting into a cross flow at inclination angles of 30°, 60° and 90°, across a range of different blowing ratios. The acquired velocity fields were coupled with reduced-order model reconstructions of the acquired velocity fields and vortex identification methods to understand the fluidic mixing characteristics and turbulent interactions produced with varying jet velocity and inclination angle, relative to the cross flow. For the investigated blowing ratios, the development and convection of high momentum regions were prominently observed across the flow field at lower jet inclination angles. Greater mixing of the jet flow with the cross flow was observed across higher inclination angles, largely attributable to the distinct formation of coherent vortex structures. The initial vortex formation process was observed to occur differently with varying jet inclination angle, with stream wise vortices forming downstream of the oscillator exit across shallower inclination angles, and transverse vortices forming adjacent to the oscillator exit across steeper inclination angles. This change in vortex rotation axis was observed to align with the peak shear regions of the flow, which was directly related to the jet orientation with respect to the free stream.