Thermo-physical properties of phase change materials -Enthalpy Porosity approach

[sumeet94]

Hello everyone

I want to know about the thermo-physical properties of phase change materials (PCMs) in the Entalpy-Porosity technique used in the Ansys Fluent solver. Usually, the properties such as density, specific heat, and thermal conductivity of PCM considered as constant in most of the literature. But, this properties should be considered as different for the solid and liquid phases, and the arithmetic average value of solid and liquid in the mushy region; else temperature dependent for both solid and liquid phase. However, in most of the research papers, they consider either solid or liquid instead of both. Does it going to affect the PCM melting and solidification fraction when the properties of PCM considered either to be solid or liquid or both?

Thank you

      

[Rob]

The model is a simplification, and that comes with some assumptions. There's nothing stopping you adding in temperature dependent properties, but exercise caution trying to expand/contract a solid and do not set two property values at a single temperature. 

[sumeet94]

Thank you for your response.

Can you please highlight the assumptions or provide any references?  

[Rob]

It's covered in the Documentation - solidification and melting model.  Click on Help in the Fluent Solver.