modeling thermal paste
 

I am using Star CCM+. Does anybody have suggestions or a way to model thermal paste or silpad between components and an heat sink. I am hoping I dont have to model a thin lay in Solidworks then import into Star CCM since that would result in some very small elements due to the thin nature of the paste or silpad material.

Model it as a contact resistance. Thermal paste is typically given an equivalent contact resistance rating, use that as the contact resistance and you are set to go. With the contact resistance model you do not have any material between the two surfaces in contact so you do not need to CAD it. You just need to create the interface between your two surfaces (which you should already have done). You can find the contact resistance in the interface properties (I believe).