Jet-Driven Cylindrical Cavity Oscillators

Abstract

The effects of cavity diameter, jet-exit distance, and flow rate on the performance of a jet-driven cylindrical cavity oscillator are investigated experimentally in this study. The cavity oscillator is driven by an air jet that enters the cavity radially through a nozzle located on the periphery of the cavity. The air leaves the cavity perpendicularly to the entering flow through a tube that has its axis parallel to the axis of the cavity. The operating frequencies are found to agree with the eigenfrequencies of the cavity; however, the regions of operation at these frequencies are shown to depend on the flow rate and to exhibit characteristics similar to those of a multistage, jet-edge resonator. The results for several cavity diameters are correlated in terms of a dimensionless frequency and a cavity Reynolds number. Schlieren still photographs and high-speed motion pictures are used to observe the motions of the jet.