Phase Change Material in Glass-Coated Circular Chamber, ANSYS Fluent CFD Simulation Tutorial

The present problem simulates the performance of PCM in Glass-Coated Circular Chamber by ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

This PCM is evenly distributed inside the chamber. PCMs are materials with inorganic or organic compounds that are capable of absorbing and storing large amounts of latent thermal energy.

Thermal energy storage in these materials is achieved during the phase change process (solid phase to liquid or vice versa); So that when the phase changes from solid to liquid, they absorb heat from the environment, and when the phase changes from liquid to solid, they return the heat to the environment.

These phase-change materials have different melting or freezing temperatures.

Therefore PCM is used in heating and cooling systems; For example, these materials receive ambient heat on a hot day in the form of latent heat and melt, and then, in the cool air of the night, return the heat to the environment again, by changing the phase and solidification process.

For the present modeling, a glass coating around the chamber containing phase change material with a constant temperature of 338.15 K has been used, which is responsible for transferring heat to the phase change material.

The 2-D geometry of the model is designed using Design Modeler software. The present model includes a circle with an outer radius of 0.0335 m and an inner radius of 0.032 m. The meshing has been done using ANSYS Meshing software, and the mesh type is unstructured. The element number is 4797.

CFD Methodology

Since the nature of the PCMs of the present model is based on the phase change between solid and liquid phases, the solidification and melting model has been used for the simulation. This PCM is in the initial state of the simulation at 332.15 K.

To use the solidification and melting model, the maximum temperature at which only the solid phase exists (T_solidus), the minimum temperature at which only the liquid phase exists (T_liquidus), and the latent heat of solvent melting in the pure state (Pure solvent melting) must be used.

Because the simulation process is transient, the simulation process is performed in a time interval of 250 minutes (15,000 seconds) with a time step of 600 s.

Phase Change Material Conclusion

At the end of the solution process, liquid mass fraction and temperature contours were obtained at different times with intervals of 40 minutes.

Also, a graph of changes in the amount of liquid mass fraction over time is obtained. As it is obvious, the liquid mass fraction increases in terms of time, and the solid mass fraction decreases consequently