Desperate ! Fan model !!!

Boris

Following is the problem I encountered

In a complex air flow system ( one in several out with complex geometry), there is a powerful fan ( pressure jump 10000 Pa) which drives the air flow. A pressure jump model of fan was used in the previous simulation to predict the air flow and pressure distribution without the consideration of temperature variation at that time. Now, I want to rerun the model with the activation of energy equation so that I can predict the air temperature variation along the flow path. For this purpose, the air density is changed to ideal gas. After reruning the model, I get a converged solution. However, I find that the temperature ( and enthalpy ) drops after the fan, although the static pressure and air density jump after the fan. In fact, the temperature (and enthalpy also) is expected to rise due to the compression of the fan. So, I suspect that the pressure jump model of fan may not suit to the compressible flow where the density and energy variations are considered. Please advise how to rectify this problem to produce correct results.

Please help. Thank you in advance.