Experimental Studies on the Load Characteristics of Low-Speed Droplets Impinging onto Surface

Droplet impingement on a wall is a fundamental scientific problem with wide engineering applications. When a droplet impacts the surface of an aircraft, it generates shock waves, airflow disturbances, and splashing phenomena. This not only has a negative impact on the aerodynamic performance and stability of the aircraft but also obstructs the field of view of optical sensors or causes distortion in optical devices. It can also damage the aircraft's structure, thus it’s vital to assess the droplet impact force for flight safety. However, droplets are often treated as rigid spheres for simplicity, but this does not reflect the real physical situation. In this paper, we utilized high-precision force sensors and high-speed imaging technology to experimentally investigate the impact dynamic of droplet impingement on a dry wall. The temporal evolution of force, the associated morphology changes and their relationship during collisions were analyzed systematically, we also elucidated the physical mechanisms underlying flow phenomenon. An unified and accurate mechanical model were established for droplet impingement, providing guidance for related engineering designs.