An Experimental Investigation of High Subsonic Flow Over an Off Axis Longitudinal Cavity with Antiresonance Devices.

摘要

This study is a preliminary effort to reduce the level of the resonance and to provide a means of predicting the pressure gains and resonant frequencies associated with a forward facing cylindrical cavity in high subsonic flow. The basic model was an ogive cylinder fitted with an off-axis longitudinal cavity. Eleven different suppression devices were investigated. Transmission line theory was used very effectively to predict the pressure gains and resonant frequency when the flow was stagnated in the cavity and to predict the resonant frequency in flow situations. The resonant frequency occurred at or near the fundamental mode frequency of a right circular cavity. The most effective anti-resonance device, a side relief hole, reduced the RMS pressure in the cavity by a factor as great as 23. Helmholtz resonators placed in the cavity were also shown to be effective, reducing the RMS pressure by a factor as great as 6.