PROJECT: NUMERICAL STUDY OF SINGLE AIR BUBBLE FORMATION IN VISCOUS LIQUID
TOOLS:   OpenFOAM v9, ParaView

1. PROJECT OVERVIEW

This project simulates the dynamics of a single air bubble forming from a submerged nozzle in a quiescent viscous liquid. It migrates the numerical study performed by Quan and Hua (2008) to the OpenFOAM environment using the 'interFoam' solver (Volume of Fluid method).

The project validates the solver against experimental air-water data and performs parametric studies on:
1. Liquid Viscosity
2. Surface Tension
3. Gas Density

2. FOLDER STRUCTURE

The folder contains the following directories:

- 0_Validation_Water/      : Base case setup for Air-Water validation.
- 1_Viscosity_Study/       : Setup for varying liquid viscosity.
- 2_SurfaceTension_Study/  : Setup for varying surface tension.
- 3_Density_Study/         : Setup for varying gas density.

3. PREREQUISITES

To run these cases, you need:
1. OpenFOAM v9
2. ParaView

4. HOW TO RUN THE SIMULATIONS

Each case folder contains an 'Allrun' script that automates the meshing, initialization, and solving process.

--- A. VALIDATION (Air-Water System) ---
1. Open a terminal inside '0_Validation_Water'.
2. Run the command: ./Allrun
3. Once complete, view results: paraFoam
   (Compare the alpha.water interface with Figure 2 of the report).

--- B. PARAMETRIC STUDY: VISCOSITY ---
To study different viscosities (e.g., 4.2 cP, 68 cP), you must modify the kinematic viscosity (nu) in the 'constant/transportProperties' file.

Formula: nu = dynamic_viscosity / density
(Density of liquid = 1200 kg/m^3)

Values to set for 'nu' (Liquid phase1):
- For 4.2 cP : set nu = 3.5e-06
- For 68 cP  : set nu = 5.66e-05
- For 850 cP : set nu = 7.08e-04

Steps:
1. Go to '1_Viscosity_Study/constant/transportProperties'.
2. Edit the 'nu' value for water phase.
3. Run: ./Allrun

--- C. PARAMETRIC STUDY: SURFACE TENSION ---
To study surface tension effects:
1. Go to '2_SurfaceTension_Study/constant/transportProperties'.
2. Edit the 'sigma' value (e.g., 0.015, 0.030, 0.060, 0.120).
3. Run: ./Allrun

--- D. PARAMETRIC STUDY: GAS DENSITY ---
To study gas density effects:
1. Go to '3_Density_Study/constant/transportProperties'.
2. Edit the 'rho' value for phase2 (Gas).
   (e.g., change from 1 to 10, 50, or 100).
3. Run: ./Allrun
