● A shock-induced fluid-structure interaction is highlighted by using a free-flight cylinder model under an impact of a shock wave. ● Luminescent Imaging of the motion-capturing pressure-sensitive paint method captures spatiotemporal pressure on the free-flight object caused by an impact of a shock wave. ● Spatiotemporal pressure of the object during its motion is captured and compared with a stationary object for validations of the measured results. The interaction of sonic booms and shock or blast waves with structures often results in debris in free flight due to potential structural damage. Understanding fluid-structure interaction through structural responses to applied pressure and fluid-induced forces may be used by engineers to accurately predict debris dynamics. The motion-capturing pressure-sensitive paint (PSP) is introduced to experimentally measure the pressure distribution of a model exposed to a shock wave and subsequent flow. PSP has benefits compared to traditional device-based pressure transducers due to the inability to install these devices without changing weight distributions and flight dynamics. The motion-capturing PSP has been shown to provide a transient pressure distribution during the motion of the model. This work aims to determine if the motion-capturing PSP method is applicable to studying the debris problem by measuring the surface pressure of a simulated piece of debris in a shock tube. An unsecured 10 mm diameter cylinder model was exposed to a shock wave, leading the model to be in free flight due to the flow generated by the shock wave, and luminescent output from the PSP was recorded via a high-speed camera. When exposed to post-shock wave flow, the motion-capturing PSP shows a high-pressure region at the leading edge and a dynamic pressure distribution across the model. The measured pressure distribution qualitatively matches the expected results for flow around a cylinder and shows good qualitative agreement with fixed model results. This indicates that motion-capturing PSP may be a useful tool in studying free-flight debris.
Slusher et al. (Sun,) studied this question.