Learning Forum

[harshit gupta]

What is the role of thermal expansion coefficient in solidification simulation in ansys fluent? and what should be the value of thermal expansion coefficient for solidification of water. This data we need to fill in the material properties I am wondering that this property was not asked in the old fluent version but asked to fill in 2022R2. 

[Rob]

Did you turn on the buoyancy option? That looks to be new and should be covered in the documentation. 

[harshit gupta]

I am using the Boussinsq approximation for the density in the material properties window for the buoyancy.

Is there any other option to turn on/off buoyancy?

Please tell me and thanks for the reply

[harshit gupta]

I had considered the gravity also as -9.81m/s2

[Rob]

OK, with Bousinesq there's an expansion coefficient. There's also a setting in the solidification panel in 23R2. 

[harshit gupta]

How to model the change in the volume of the ice (when it solidifies from water) due to the change of temperature/density, in the ansys fluent

[Rob]

You'll need to add in a temperature dependent density, but with water being rather strange you may nee expressions or a UDF. Note, the ice won't float: read how the model works.