Executive Summary : | The impact dynamics of solids on water surfaces are crucial in various fields such as defense, space technology, water transport, marine, and coating. These devices require minimal impact force and drag reduction, and research on superhydrophobic surfaces or lubricant impregnated surfaces is limited, particularly at high speeds. These surfaces are expected to sustain a cavitating air layer, reducing impact and drag force through induced slip. However, previous research has only investigated superhydrophobic surfaces at low speed regimes with spherical geometry, which may not be feasible for real-world applications.
The proposed work aims to investigate the physics of this problem involving solids with easily fabricable superhydrophobic surfaces and lubricant impregnated surfaces with different surface textures and wettability properties at different impacting conditions, including at high-speed regimes. Two custom-made experimental setups will be used to investigate the impact dynamics of these solids. A compressed air-based propulsion system will be used to propel solids at different speeds, while a water tank made of transparent acrylic sheets will be used to observe underwater phenomena upon solid impact. A high-speed camera will capture the evolution of the cavitation layer and the motion of the solid at millisecond resolution. A proper understanding of the physics will help in designing energy-efficient impacting projectiles or unmanned underwater vehicles with efficient control and maneuverability. |