Experimental investigation of dynamics of large-scale vortex structures of a sweeping jet emitted into a slot channel

The experimental study was performed for a submerged turbulent sweeping jet emitted into a slot channel with height h = 4 mm. A sweeping turbulent jet was generated by a fluidic oscillator with two feedback channels and the exit nozzle with the throat width d = h. The working fluid was distilled water. The two-component velocity fields were measured using time-resolved particle image velocimetry. In the range of Reynolds numbers from 1500 to 8000, experimental data on the structure and dynamics of the flow of a sweeping turbulent jet in a slot channel were obtained. The results show that the outflow of a sweeping jet into the slot channel leads to the formation of stable large-scale quasi-two-dimensional vortex structures. The passing frequency of these structures depends on the jet sweeping frequency produced by the fluidic oscillator. An analysis of the comparison of investigation results with the experimental data available in the literature shows that in the case of a slot channel with the ratio h/d = 1, there is a decrease in the jet oscillation angle and a change in the distribution of the average and pulsation characteristics of the sweeping jet. In addition, analysis of the results shows that the dimensionless jet oscillation frequency decreases with increasing Re number.