Short-range repulsive force model for near-contact interactions of bubbles

Area of Science:

• Multiphase flow dynamics
• Fluid mechanics
• Computational physics

Background:

• Simulating bubble interactions requires accurate models for near-contact dynamics.
• Previous methods often rely on computationally expensive adaptive mesh refinement.
• Nonphysical bubble coalescence can occur in simulations without proper short-range interaction modeling.

Purpose of the Study:

• To introduce a simple mesoscale repulsive force model for bubble-bubble near-contact interactions.
• To enable simulations on coarse meshes, avoiding excessive computational cost.
• To prevent nonphysical bubble coalescence in numerical simulations.

Main Methods:

• Developed a short-range repulsive force model, inversely proportional to the third power of distance.
• Validated the model against two experimental setups involving rising bubbles.
• Determined model parameter K using data from a water-glycerol mixture experiment.
• Simulated various bubble interaction scenarios (coalescence, bouncing coalescence, bouncing separation) in pure water.

Main Results:

• The repulsive force model effectively prevents nonphysical bubble coalescence on coarse meshes.
• Model parameter K was successfully determined through experimental data.
• Simulations accurately reproduced experimental observations of bubble coalescence, bouncing coalescence, and bouncing separation.
• The model demonstrates good agreement with experimental results for different bubble sizes and initial separations.

Conclusions:

• The proposed short-range repulsive force model is a computationally efficient and accurate method for simulating bubble interactions.
• Its simplicity allows for easy integration into existing computational fluid dynamics codes.
• The model shows potential for extension to more complex scenarios involving multiple bubbles or droplets.