difficulties with fluent simulation
 

I'm working on simulation of flow behind ahmed body. I began my computation, but there is always the message "reversed flow on pressure outlet". I added dimension on pressur outlet but the problem still remain. I don't know if my boundary conditions (velocity inlet: 40m/s; turbulent intensity 10%; turbulence lenght scale 0.001 m; pressure outlet: gauge pressure 0 Pa; backflow turbulent intensity 10%; backflowturbulence lenght scale 0.001 m and operating conditions (gauge pressure 101325 Pa; gravity unchecked) are bad or my inializing conditions (i compute from all zone with gauge pressure equal to 0). Th turbulence model is k-epsilon realizable.
Please i need your help!!!

A quick reply will be welcome

This means, you have a flow at the pressure outlet into the domain. Normally, this happens when the outlet is too close to some relevant inside your domain. If you move the outlet further downstream, the error will vanish.