Abstract:
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.