Large bubble entrapment during drop impacts on a restricted liquid surface

The behavior of millimetric drops impacting on a gas-liquid interface restricted by surrounding walls is studied using a high-speed video camera. A novel phenomenon of large bubble entrapment is observed in experiments. It is found that the large bubble formation is not only dependent on the impact velocity of the drop, but also the shape of drop at the moment of contact with the liquid surface and the distance from the impact point to surrounding walls. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3703674]