Three flow regimes of viscous jet falling onto a moving surface

TL;DR

This study investigates the behavior of a viscous jet falling onto a moving surface, identifying three flow regimes based on jet shape and providing a combined theoretical and experimental analysis.

Contribution

It introduces a classification of flow regimes for viscous jets on moving surfaces using a new theoretical model and experimental validation.

Findings

Identification of three distinct flow regimes: concave, vertical, convex.

Qualitative agreement between the model predictions and experimental results.

Characterization of flow regimes in terms of process and material parameters.

Abstract

A stationary viscous jet falling from an oriented nozzle onto a moving surface is studied, both theoretically and experimentally. We distinguish three flow regimes and classify them by the convexity of the jet shape (concave, vertical and convex). The fluid is modeled as a Newtonian fluid, and the model for the flow includes viscous effects, inertia and gravity. By studying the characteristics of the conservation of momentum for a dynamic jet, the boundary conditions for each flow regime are derived, and the flow regimes are characterized in terms of the process and material parameters. The model is solved by a transformation into an algebraic equation. We make a comparison between the model and experiments, and obtain qualitative agreement.