Simple Melting Problem
 

Hy all fluent users!

I am a fluent beginner and i want to set up a melting/solidification problem. I started with the easiest model, but i still have troble with that.

My model is a cuboid. All walls are adiabat except one. This one is heated (T=600K). The properties of the pcm are all set to constant:

• density = 2260 kg/m^3
• specific heat = 1820 j/kgK
• thermal conductivity = 0.5 W/mK
• solvent melting heat = 178000 j/kg
• solidus temperature = 580.65 K
• liquidus temperature = 581.65 K

Solution Controls: default
Initial value for temperature: T = 300 K
Time step: t = 2 s

After the first layer is molten, it takes a long time that the melting process continues. There is always some time between the melting of two layers. It dosn't melt consistent. The bigger i choose thermal conductivity and the lower i choose density, the shorter become the time between the two layers (whre no melting is occurring). see the picture attached!!

What do I have to change to get a consistent melting???

Thank you for your help!!