I am using the flow simulation program, and I am defining a contact resistance from a circuit board to an aluminum mounting surface.

I am defining the resistance as “Zero resistance” in the menu.

The results however show a large temperature difference between the interfacing surfaces.

75 deg C vs 97 deg C (22 deg c difference).

It is as though the contact resistance of zero is having no effect, even though it is defined as zero.

Would someone know what might be wrong here?

Thank you.