Break-up of the Taylor bubble

High-resolution direct numerical simulation is used to study the motion of a Taylor bubble in a cylindrical microtube under conditions that lead to the bubble break-up. It is observed that the initial bubble elongates and deforms such that its front part retains a bullet-like shape while its back part forms a skirt shape. Subsequently, the carrier fluid surrounded by the skirt penetrates into the bubble forming a finger that transitions into a bulb shape. The bulb then increases in size until it touches the near-wall liquid film and as a result splits the bubble into two comparable daughter bubbles. Various dynamical features of this break-up process are explored and described in detail.