Hi @dEEpAk135
Your objective is to observe airflow patterns, not the fan design. All fans are designed to create a pressure differential, which in turn drives airflow either inwards or outwards. However, boundary conditions can greatly simplify this if you don’t need to explicitly model the flow patterns and turbulence in the fan’s near-region. My advice is to thoroughly study the role of boundary conditions in numerical simulations.
Regarding your other question about exhaust air, again, it’s essential to understand boundary conditions and their various definitions. It’s a complex topic, as you can either impose a velocity flow (inwards or outwards) or set a pressure differential, which will then drive the flow.
Lastly, what you’re observing in the tutorial isn’t a temperature field, but the transport of a passive scalar. This represents the diffusion and convection of a “passive” tracer substance that does not interact with the flow but is carried within the domain.