Influence of Chamber Geometry and Operating Conditions on the Performance of Feedback-Free Fluidic Oscillators

摘要

The feedback free fluidic oscillator uses the unsteady nature of two colliding jets to create a single oscillating outlet jet with a wide sweep angle. These devices have the potential to provide additional combustion control, boundary layer control, thrust vectoring, and industrial flow deflection. The work presented in this paper uses two-dimensional computational fluid dynamics, CFD, to analyze the jet oscillation frequency over a range of operating conditions and to determine the effect that geometric changes in the oscillator design have on the frequency. In addition, microphone data gathered from six 3D printed fluidic oscillators is used to validate the CFD and correlate the 2D analysis to several different oscillator aspect ratios. Results presented in this paper illustrate the changes in jet oscillation frequency with gas type, gas temperature, operating pressure, pressure ratio across the oscillator, aspect ratio of the oscillator, and the frequency trends with various changes to the oscillator geometry.