Droplet deposition into a circular hole with sharp/rounded edge

Precise control of droplet deposition into holes is essential for advanced manufacturing applications, yet this area remains largely unexplored. Previous studies have examined droplet deposition on open or weak confined geometries, but deposition into holes presents fundamentally different challenges due to strong confinement effects. This study provides the first comprehensive numerical investigation of droplet deposition into circular holes with sharp and rounded edges. The confined hole geometry creates distinct pressure patterns, altered spreading behavior, and enhanced heat transfer compared to open surfaces. These effects lead to unique solidification patterns characterized by curved solidification fronts and narrowing flow channels within the hole. Systematic analysis of key parameters reveals that impact velocity has the greatest influence on deposition performance, followed by substrate temperature and droplet temperature. Using optimization methods, we identified an optimal parameter combination that increases the filled volume ratio by 33 % compared to standard condition. This optimized approach also improves performance for holes with rounded edges, achieving better material integration and fewer defects. These results establish the first quantitative framework for controlling droplet deposition into holes, with direct applications to those manufacturing processes requiring accurate material placement in confined spaces.