Comparison of Droplet Spreading on a Stationary and Moving Surfaces

The dynamics of a water droplet impinging on a solid surface has long been of interest since the phenomenon can be seen in a variety of industries such as spray coating, heat exchanger, and aircraft icing. Many investigations have been given to the impingement where the droplet freely falls on to the stationary surface by the gravitational force. Recently, the target of the droplet impingement study has been broadened in order to take into account the influence of the motion of the air. However, the influence of the motion of the solid surface has not been fully understood. In this study, the experimental setup is developed in which the solid surface moves toward stationary water droplet. With this setup, the maximum spreading diameter is measured by changing the droplet diameter as well as the speed of the solid surface. The presentation will address the comparison in the maximum spreading diameter between conventional free fall and developed setup.