[Costas]

Hello guys, im new to the topic so im trying to figure things out. I want to carry out a mesh convergence for the ahmed model. Im using a 25 deg. slant for 40m/s. I know i have to approximate double my mesh size to see whether me residuals have converged. I should be plotting a graph to show convergence of the number of elements against some other variable. What would be the most appropriate variable to take and how woould i take its value? Thank you