Numerical simulation of ligament-growth on a spinning wheel

• Growth of ligaments from liquid film on a rotating wheel is studied numerically.
• We follow the growth from embryos – small bulges rising in the radial direction.
• The results agree well with the experimental data.
• Importance of liquid film thickness and wheel’s rotational frequency is shown.
• The shown simulations can explain typical forward curvature at ligament’s tip.

Liquid ligaments can grow from perturbations in liquid film spread on a spinning wheel due to the centrifugal force acting on the film. Typically, the growth is strongly influenced by the surface tension on the evolving liquid–air interface. This phenomenon, frequently exploited in industry for the production of fibers, was investigated numerically and the Volume-of-Fluid (VOF) methodology was used to model the interface. The freely available Gerris code with adaptive mesh refinement (AMR) was used to achieve the fine resolution of the computational grid required at the evolving liquid–air interface. The results were compared with the experimental data captured by a high-speed camera. The influence of the process operating variables on the ligament growth is also presented.