Bubble Bursting in an Elastoviscoplastic Medium

This repository contains the code and supplementary material for simulating bubble bursting dynamics in an elastoviscoplastic medium. The simulation is implemented in 2D+axi (axisymmetric) configuration using the Basilisk framework.

Publication

This work has been published in the Journal of Fluid Mechanics. If you use this code or data in your research, please cite:

@article{balasubramanian2024bursting, 
    title={Bursting bubble in an elastoviscoplastic medium}, 
    volume={1001}, 
    DOI={10.1017/jfm.2024.1073}, 
    journal={Journal of Fluid Mechanics}, 
    author={Balasubramanian, A. G. and Sanjay, V. and Jalaal, M. and Vinuesa, R. and Tammisola, O.}, 
    year={2024}, 
    pages={A9}
}

The article can be found at:

Background

The simulation models the bursting dynamics of a bubble in an elasto-viscoplastic medium, which exhibits both elastic and viscoplastic behavior. The physics includes:

• Two-phase flow with surface tension
• Elasto-viscoplastic rheology
• Axisymmetric geometry
• Log-conformation formulation for numerical stability

Implementation

Key Files

• 01_code/burst_evp.c: Main simulation file implementing the physics
• 01_code/log-conform-EVP.h: Implementation of log-conformation method for viscoelastic models
• 01_code/saramito-EVP.h: Implementation of Saramito's elasto-viscoplastic model
• 01_code/adapt_wavelet_limited.h: Adaptive mesh refinement implementation

Key Parameters

• Bond: Bond number (ratio of gravitational to surface tension forces)
• J: Dimensionless yield stress
• Deb: Deborah number (ratio of relaxation time to observation time)
• B: Solvent to total viscosity ratio
• tmax: Maximum simulation time
• DT_MAX: Maximum time step

Numerical Methods

• Grid: Adaptive mesh refinement with levels from LEVEL (8) to MAXlevel (11)
• Time integration: Centered Navier-Stokes solver
• Interface tracking: Volume-of-Fluid method with tension
• Error tolerances:
  • Fraction error (fErr): 1e-3
  • Curvature error (KErr): 1e-4
  • Velocity error (VelErr): 1e-2
  • Vorticity error (OmegaErr): 1e-3

Getting Started

Prerequisites

• Install the Basilisk framework
• Ensure you have a C compiler with OpenMP support
• Python 3.x for post-processing

Initial Configuration

The simulation requires an initial shape file that defines the bubble geometry:

• Bo0.0010.dat: Initial bubble shape for Bond number 0.001
• Place this file in the same directory as burst_evp.c
• For details of how this shape is obtained, please refer to repo: VatsalSy/Bursting-Bubble-In-a-Viscoplastic-Medium.

Running Simulations

1. Compile the code with OpenMP support:

# Compile the code
qcc -O2 -Wall -disable-dimensions -fopenmp burst_evp.c -o burst_evp -lm

# Set the number of OpenMP threads
export OMP_NUM_THREADS=4

# Run the executable with Plastocapillary (J) and Deborah (Deb) numbers
./burst_evp 1.0 0.5  # Example: J=1.0, Deb=0.5

Outputs

Output Files

The simulation generates several output files:

• intermediate/snapshot-*.dat: Simulation state at regular intervals
• timestep.txt: Time stepping information
• log: Contains kinetic energy and other diagnostic data
• 01_pp/png/: Directory for PNG output files
• 01_pp/pdf/: Directory for PDF output files

Visualization and Post-processing

The repository includes supplementary materials:

• 02_videos/: Contains 66 videos showing bubble dynamics
• 03_supplementary_plots/: 79 plots analyzing various aspects
• 04_graphical_abstract/: Visual summary of key findings

Contact

If you need some additional data that might be of interest to you, please don't hesitate to contact us at:
Arivazhagan G B
Vatsal Sanjay
Outi Tammisola