EXPERIMENTAL STUDY AND EDUCATIONAL EXPLORATION OF HYDROPHILIC/HYDROPHOBIC SPHERES IN WATER ENTRY

To address the challenges of abstract theoretical concepts and limited experimental visualization in fluid mechanics pedagogy, this study revamped an experimental teaching framework centered on the water entry of hydrophilic/hydrophobic spheres. By integrating an experimental platform combining high-speed photography and image processing, it focused on analysing dynamic capture methods for gas-liquid interfaces and quantification of contact line evolution. Through comparative analysis of hydrophilic versus hydrophobic sphere water entry processes and similarity law-based analysis, the framework guides students to explore wettability-regulated cavity formation mechanisms and the dominant role of the Froude number. Leveraging wettability-induced asymmetric cavity evolution, this approach employs problem-driven experiments to deepen students’ analysis of flow-field evolution patterns while enhancing core competencies in boundary identification and similarity law-based engineering applications.