Modeling film flows down a fibre influenced by nozzle geometry

TL;DR

This paper develops a coupled model to analyze how nozzle geometry influences the flow regimes and droplet formation in thin films flowing down a vertical fibre, aligning well with experimental observations.

Contribution

It introduces a weighted residual model that incorporates inertia, surface tension, gravity, and stabilization to predict flow behaviors influenced by nozzle size.

Findings

Model accurately predicts droplet properties

Flow regimes vary with nozzle diameter

Good agreement with experimental data

Abstract

We study the effects of nozzle geometry on the dynamics of thin fluid films flowing down a vertical cylindrical fibre. Recent experiments show that varying the nozzle diameter can lead to different flow regimes and droplet characteristics in the film. Using a weighted residual modeling approach, we develop a system of coupled equations that account for inertia, surface tension effects, gravity, and a film stabilization mechanism to describe both near-nozzle fluid structures and downstream bead dynamics. We report good agreement between the predicted droplet properties and the experimental data.