Capillary instability of a viscous liquid thread in a cylindrical tube

摘要

We study axisymmetric breakup and drop formation of a liquid thread confined in a cylindrical tube by using a long wave model. The limit with large viscosity contrast is investigated, consisting of a highly viscous core and a less viscous annulus. Satellite drop formation near pinching is found to be dependent on the location of the tube wall, while inertia is found to have little effect. It is also shown that main drops tend to form so called "plug with collar" structures when the tube wall is close to the thread interface so that rings of fluid are trapped inside the plugs. Finally, our numerical simulations show that a double cone structure occurs on the breakup and the cone angles are fixed, even though self-similar solutions may not exist.