[lcarasik]

I would start your analysis using an isothermal flow simulation. This should give you an idea of flow physics before you start attempting to model the heat transfer occurring. You should not attempt to set your outlet boundary condition as a function of your inlet.

After running an isothermal set of test runs, I would recommend engaging the segregated fluid temperature model. Set your inlet boundary to a velocity boundary and define your inlet temperature (I'm assuming a set inlet temperature that does not vary). On your servers, I would set their boundaries (or an approximation it) using a set temperature or heat flux that the air is exposed to. Set your outlet boundary to a pressure outlet and you shouldn't have to set the temperature for it. (Also, I recommend looking into invoking the buoyancy source terms if there is a large enough density change of the air after getting heated by the servers.)

This should get you started, but I'd recommend you read over meshing sensitivity studies, basic turbulence modeling, and heat transfer modeling. Also, I recommend you contact CD-Adapco (if you are able to) with questions like this. They should be able to provide more guidance.