Blister formation phenomenon for droplet impact under different liquid pool depths

Droplet impact in the liquid pool is an ubiquitous phenomenon in nature and it has essential scientific research value. Via the high-speed camera technology, the extraordinary blister formation phenomenon on the liquid pool surface is studied when the droplets fall from various heights of 3m to 15m to the liquid pool of different depths. The effects of the depth of the liquid pool and the We number of droplets on the blister formation are given. It is shown that a droplet can form a blister at the center of the impact when it hits the shallow pool. However, when it hits the deep pool, it forms an annular blister, which then develops into one or two blisters, and the blister formation position is not at the location of the impact. In addition, under the influence of factors such as the droplet impact velocity, the liquid pool depth and the secondary droplet drop, the blister formation phenomenon for the droplet impact presents complex probability distri-bution characteristics.