Thanks Chicopee and georgeverghese
I think I am a bit further now in my understanding. When I was comparing the
1. adiabatic model
2. and the isothermal model
I was making one crucial mistake (I think); I used the same efficiency coefficient. But in fact for the isothermal model I should use...
I was talking about a fan; axial or radial with a dP of max 20kPa. But in principle I want to understand why the work I calculate wit the adiabatic model is less than for the W=VdP calculation.
Dear forum
I have been trying to calculate the work done by a fan on a gas flow in two ways, but I get two different values of power.
The first method is the W=V * dP
(I guess this is assuming isothermal compression). I then use the power calculated as a measure of the internal energy...