Comparative Analysis of Optical and X-ray imaging Techniques for Cavitation Inception*

Curved surfaces like propeller blades are prone to cavitation, a phenomenon that causes structural damage. In this study, comparison of high-speed optical imaging and X-ray imaging for small scale cavitation in a dynamic flow is investigated.  A high-speed camera is used for obtaining inception locations on the divergent of a venturi type section with various roughness ranging from 3 to 110 micrometers. Factors such as inceptions points, efficient tracking of the nuclei, information about gaseous and liquid phases, void fraction measurement and cavitation bubble collapse, are studied between X-ray and optical imaging techniques. This will help us provide more insight into the flow field structure and its dynamics. With exceptional spatial and temporal resolution in X-ray imaging, visualization of inception for various roughness will help us study quality of cavitation bubbles and boundary layer dynamics. The findings from this study will help us examine the trade-offs between experimental complexity, depth of information and multi-scale analysis for different imaging techniques for inception flow.