Fluidic Oscillator with Variable Sweep and Inclination Angles

Abstract

This work introduces a fluidic oscillator design that allows control over the sweep and inclination angles, independent of the supply flow rate. These capabilities are made possible by injecting fluid from four control ports located in the vicinity of the throat of a feedback-type fluidic oscillator, thus avoiding the addition of any moving mechanical parts. Hot-wire measurements, water flow visualizations, and numerical analyses were used to characterize the fluidic oscillator. The sweep and inclination angles were calculated numerically and extracted from the flow visualizations. Numerical analyses indicated that the sweep angle can be varied from 17 to 70 deg, and the inclination angle can be varied up to 20 deg based on the amount of control flow applied for the considered control port geometries. The oscillation frequencies were observed to decrease with increased control flow rate by up to 5% for the variable sweep angle design and up to 7.7% for the variable inclination angle design. Also, the increase in the inclination angle was accompanied by a decrease in sweep angle, and the amount of this decrease was depended on the amount of the control flow applied.