Hello! I will begin the new project about the flow simulation in an engine room. In a vehicle engine room, there is a fan in order to cool the interior. Do you know any journal or book related in this theme? Would you like to give a reply? Thanks.

A fan is for low pressure application. Normally, you should have a performance chart which will give you RMP and flow rate. From there, you can derive the exit velocity, uniform, or non-uniform ( if you measure the velocity distribution ). That velocity distribution can be used as a boundary condition on the wall where the fan is located.

Gerald Schmidt (gerald@adapco.com) from Adapco did this kind of simulation for Mercedes some years ago using StarCD. They have also a nice video about this work.

You should find some answers to your questions by looking at some automotive industry databases (like Society of Automotive Engineers in US). There have been a lot of studies (both numerical and experimental) as the cooling of the engine compartment is still under research