A diffuse interface model for the analysis of propagating bulges in cylindrical balloons

TL;DR

This paper develops a diffuse interface model to analyze the formation and propagation of bulges in cylindrical rubber balloons, drawing an analogy to phase transitions, and validates its accuracy against traditional membrane models.

Contribution

It introduces a novel diffuse interface model for bulge analysis in cylindrical balloons, enabling both numerical and analytical solutions with high accuracy.

Findings

The model accurately captures bulging phenomena.

It allows bifurcation analysis of bulge propagation.

The approach provides a quantitative phase transition analogy.

Abstract

With the aim to characterize the formation and propagation of bulges in cylindrical rubber balloons, we carry out an expansion of the non-linear axisymmetric membrane model assuming slow axial variations. We obtain a diffuse interface model similar to that introduced by van der Waals in the context of liquid-vapor phase transitions. This provides a quantitative basis to the well-known analogy between propagating bulges and phase transitions. The diffuse interface model is amenable to numerical as well as analytical solutions, including linear and non-linear bifurcation analyses. Comparisons to the original membrane model reveal that the diffuse interface model captures the bulging phenomenon very accurately, even for well-localized phase boundaries.