Does any free software that can do thermal analysis?

If your a student then go to autodesk student free software, there commercial and student version is the same the difference is you do not use student version for profit

Fusion 360 might do what you need.

ANSYS provides a very limited version of their products free to students (or anybody really, as long as it's for personal use only.)

You could also consider hiring a consulting agency to do the simulation for you, if it's just a one time analysis. Much less expensive than buying a license and training workers.