Need help creating geometery
 

Hi all,
I am currently working on the fluid mechanics project. The project is about to calculate the hydroplanning forces on the moving wheel of the car. I have to work with multiphase flow (Air + water). The schematic view of the problem is attacged
The Bounday Conditions are
1-Air and water both are moving with the same speed.
2-The tire is rotating and moving at the same time.
3.Ground and walls are moving.
Please tell me how can i use Split command to split the box in two segments.
I am using ANSYS 13 for that.
Apprecite your suggestion