Effects of a Generic Store on Cavity Resonance at Supersonic Speeds

Abstract

Supersonic flow over a cavity, such as the open internal bay of a tactical aircraft, involves a variety of fluid dynamics mechanisms and different types of instabilities, including those associated with the shear layer, flow-induced resonance, and turbulence. The current study presents experimental data on the response of cavity dynamics to the introduction of various store configurations mounted at different locations within the cavity. A rectangular cavity was subjected to Mach 2 flow at Reynolds numbers ranging from 4 to 16 million. Measurements were carried out inside the cavity and on the flow-facing surface of the store to capture the cavity acoustics and unsteady loading on the store. Results show that, with an increase in the Reynolds number, the magnitude of pressure fluctuations increases, whereas the frequency of dominant tones remains the same. In general, the presence of a store results in suppression in broadband noise, with amplification/suppression of different Rossiter modes. The location of the store with respect to the cavity shear layer plays an important role in the cavity acoustics. There is a strong correlation between the acoustic signatures measured at various locations in the cavity and on the store surface, indicating the global resonance.