Corrdinates

Valentina

I am not very familiar with Fluent, just started learning and I am doing pretty good except for one thing..so far. I am trying to simulate airflow over a tire, which is supposed to rotate. Problem is that I cannot seem to figure out the rotating axis origin -or the point around which is the tire has to rotate. I know it is the center of the tire, but i don't know what its coordinates are. The tire was imported from a solid works file, and somebody else did the mesh so all I have is the case file. I know there is a way to find the coordinate but it seems like I am doing something wrong because I can't get them! Can somebody give me a step by step explanation how to do it. Also I know that i need to click on the point, but how do I click exactly on the center? thanks