About Phase Change Materials

[Anonymous]

Hello all,

I am simulating the PCM's melting process from solid state to liquid state by using Autodesk cfd. As far as I know, after being heated for some time, solid state PCM in the liquid phase will sink down towards the bottom due to the density difference of liquid PCM and Solid PCM.

Can Autodesk CFD handle this phenomenon?

And I find that once define a material as Solid, it will always be solid state no matter how much heat transfer into it. Am I correct?

Best

Wen.

[Jon.Wilde · Accepted solution]

Thanks for posting here 😉

You are correct, this actually isn't something that we could model.

We can capture property changes with the change in temperature but not actual physical shape change.

Thanks for asking though and please do let us know if we can help with any other models.

Jon

[Anonymous]

Hi, Jon.

You said "We can capture property changes with the change in temperature but not actual physical shape change."

If I let the density change with the change in temperature, For example, the temperature of 23C, the density is 1700KG/m3; when the temperature reaches 30C, the density is 1500KG/m3.

1) In this situation, is the conservation of mass still met? Because I think the volume can not change during the heating process.

2) If conservation of mass does not met, than I have to define the value of density to a constant value. How can I simulate the nature convection phenomenon in AUTODESK CFD? As far as I know, Nature convection is only caused by density difference in the fluid occurring due to temperature gradients.

Waiting for your reply. Thanks