Impact force of a low speed water droplet colliding on a solid surface

The impact forces of the low-speed water droplet colliding on a light and tiny aluminum plate were measured by using a highly sensitive piezoelectric force transducer. The one-degree freedom vibration model was employed to analyze the oscillation of the measured force signals, and the plate vibration was confirmed as the cause through elaborately designed experiments. The force data were obtained by using the low-pass Finite Impulse Response filter and was verified to be reliable. The effects of impact velocity and diameter of droplets on the impact force evolutions and peak forces were investigated. The results revealed that the impact process of a liquid droplet is quite different from that of a solid ball in the frequency spectrum and in the power function of the peak force. The droplet impact is closer to a plastic impact, while the other behaves more nearly an elastic impact. The influence of droplet size on erosion is dependent on the impact time duration, which increases with droplet diameter. On the other hand, the impact pressure is the main cause of the material erosion when impact velocity is taken as the influence factor. (C) 2014 AIP Publishing LLC.