Impact force of a water droplet impinging on a flat surface with different types of wettability

Localized downpour is one of the reasons causing disasters such as river overflowing and landslides. In order to rescue human lives over these happens, micro aircrafts have been developed to immediately identify risks of secondary calamity. When it flies in Localized downpour, the load applied by raindrops will be applied to the micro aircraft, but any accurate evaluation has not been done yet. For the estimation of the load caused by rain droplets, impact force of water droplets with equivalent diameter of 2.0 mm to 6.5 mm were measured. Super hydrophobicity and hydrophilicity were adopt as surface wettability, and evaluated which surface property was more effective for micro aircraft.