ANSYS Fluent hardware requirements
 

I had worked with Ansys Fluent for a little bit and I have some experience, but I need to learn much more. Anyway we want to model heat exchanger with tubes inside. Tubes will be giving heat flux and we want to check out what is going inside it at different heat fluxes. In tubes are hot air. Tubes are small diameter and surrounded by water. Heat exchanger is 8 meters height and 3 meters diameter.

And now I have few questions, not sure if it possible to answer it at all, because I tried to search for it, but didn't found nothing that is useful.

First thing is how I can calculate how much cells I need for my model?

Second thing what computer with what hardware would be enough?

Links to literature are also good I would like to know more.