A capillary jet plunging into a quasi-2D slab of monodisperse foam of the same solution is studied experimentally. We show that the jet can have a drastic impact on the foam. At small speeds it inflates the channels separating the bubbles. At intermediate speeds, impact with channels creates very small bubbles. At higher speeds the jet action reverses: it now thins the liquid film up to the point of rupture, which can induce bubble coalescence. We study the mechanisms behind these processes using an elementary foam made of three soap films in contact through a Plateau border. We obtain scaling laws ruling the jet-foam interaction which transfer quantitatively from the elementary foam to the 2D foam.

Close

PrevNext

View figure in article

• Bubble dynamics
• Drop or bubble formation
• Foams