Inertia and slip effects on the instability of a liquid film coated on a fibre

Understand

To investigate the influence of inertia and slip on the instability of a liquid film on a fibre, a theoretical framework based on the axisymmetric Navier-Stokes equations is proposed via linear instability analysis.

• The model reveals that slip significantly enhances perturbation growth in viscous film flows, whereas it exerts minimal influence on flows dominated by inertia.
• Moreover, under no-slip boundary conditions, the dominant instability mode of thin films remains unaltered by inertia, closely aligning with predictions from a no-slip lubrication model.
• Conversely, when slip is introduced, the dominant wavenumber experiences a noticeable reduction as inertia decreases.