Identify one or more outlet surfaces and define the conditions.
        - 
                On the Fluids ribbon, select the Outlet tool.

             
- 
                Select one or more surfaces as the outlets.
            
 
- 
                In the microdialog, define the pressure.
                
                    Tip: The pressure is defined relative to the
                        atmospheric pressure. To set the outlet pressure equal to the atmospheric
                        pressure, enter 0.