2D transient CFD simulation of water solidification in a square cavity using ANSYS Fluent. Includes temperature and liquid fraction contours, animations, and mesh visualization.
This project investigates the solidification of water in a small square enclosure using ANSYS Fluent.
The study simulates the freezing process of water under laminar, transient conditions, where cold outer walls drive heat transfer and phase change.
- Domain: 2D square cavity
- Outer square:
0.04 m × 0.04 m - Inner square:
0.01 m × 0.01 m(centered)
- Outer square:
- Material: Pure water (from Fluent materials database)
- Initial temperature (liquid region): 2 °C
- Wall temperature: −20 °C
- Gravitational acceleration: 9.81 m/s²
- Latent heat of fusion: 334,000 J/kg
- Flow regime: Laminar
- Simulation type: Transient
- Number of elements: 494,064
- Solver: Pressure-based, SIMPLE
- Pressure discretization: PRESTO!
High-resolution 2D mesh ensuring refined gradients near the inner and outer boundaries.
- Cold walls at −20 °C induce solidification starting from boundaries.
- Gravity considered to capture buoyancy effects.
- The continuity residual stabilized and remained sufficiently low —
an acceptable convergence criterion for this type of phase change analysis.
- Time-dependent (transient) analysis
- >5000 iterations
- The simulation duration was limited, so complete solidification was not achieved.
However, the phase front evolution and temperature distribution clearly represent realistic solidification behavior.
Cold walls propagate temperature gradients inward, matching expected conduction patterns.
Formation of solid regions starts from the walls.
A mushy zone remains in the corners — due to limited simulation time.
Temperature evolution:
Solidification process:
- Heat transfers from the outer cold walls toward the inner liquid region, as expected.
- Solidification initiates near the boundaries, progressing inward over time.
- The mushy zone persists at corners due to residual heat and limited simulation time.
- Despite residual fluctuations, continuity residuals stabilized, validating the transient convergence.
- The simulation demonstrates the solidification mechanism effectively in small-scale enclosures under natural convection and conduction-driven cooling.
This CFD study successfully models the freezing of water in a confined cavity.
Even with partial solidification, the temperature gradients, phase interface movement,
and solid growth pattern are in strong agreement with physical expectations.
| File | Description |
|---|---|
geometry.png |
Geometry of the computational domain |
mesh_494064.png |
Mesh visualization |
static_temp_cont.png |
Temperature contour |
liquid_Fraction_cont.png |
Liquid fraction contour |
scaled_residuals.png |
Residuals plot |
temperature-animation.gif |
Temperature evolution animation |
solidification-animation.gif |
Solidification process animation |