Fluid–Structure Interactions on a Tunable Store in Complex Cavity Flow

Abstract

Fluid–structure interactions were studied on a store with tunable structural natural frequencies in complex cavity flow. Different leading-edge geometries, doors, and internal inserts generated cavity pressure fields more representative of an actual aircraft bay. The store loading and response was characterized using point pressure and accelerometer measurements, while high-frequency pressure-sensitive paint captured the distribution of surface pressure. In the complex cavity, the store responded to the cavity resonant tones not only in the streamwise and wall-normal directions but also in the spanwise direction. That spanwise response to cavity tones was not observed in a simple rectangular cavity because the flow in the spanwise direction was uniform and in phase. This different behavior highlights the importance of using a representative bay geometry and internal store for the prediction of the structural response in a flight environment.