A Study of Feedback Fluid Jet Oscillator With a Supersonic Power Jet: Part I: Presentation and Interpretation of the Experimental Data

Abstract

A model feedback fluid jet oscillator was constructed and run to illustrate the feasibility of producing sustained jet oscillation and provide data for analysis of such an oscillator. Experimental measurements were made on the frequency of oscillation by observing the characteristic pressures within the oscillator through oscillographic recordings. This was further confirmed by taking high speed motion pictures through a Schlieren system during jet oscillation. It was found that a certain level of primary stagnation pressure was required before jet switching and oscillation would occur. The operating frequency, which was on the order of ten cycles per sec, was dependent upon the storage volume and the feed inlet opening. The sequence of events occurring within this oscillator can be observed and interpreted from the variation of characteristic pressures. The analogy between the fluidic feedback jet oscillator and the electronic oscillator is clearly borne out from this investigation.