Natural Convection for a sphere

Hello, everybody. I am new in Simscale and I am using the tool for a school project. The teacher asked us to prove an empirical Nusselt correlation for natural convection on a sphere. He told us to use a transient simulation to study the temperature change of the sphere. Simulations are not running at all due to the Courant number, the dialogue says it is too big for the simulation. It is also showing an error when calculating the pressures due to the mesh size, but if we try to make a finner mesh we come to convergence problems.

Here is the link of the project if someone can help! Thanksss

Hey @as_nchez_zaval!

Have you had a look at that doc entry already?

@cfd_squad : can you give our user additional tips?

Enjoy your weekend!