Mick Loney

I'm modelling a number of diesel machines driving a tunnel ventilated by a forcing fan and ductwork.  I get the error message "Fresh Air Deficit" x 5 when I try to run the model.  The error persists even if I reduce the utilisation factor for the machines to 10%.  The error isnt being caused by excessive DPM levels, or by excessive temperature.  I assume its because the total flow available in the road is less than the total engine power x 0.06m3/s?  How does the software assign this error?  Is there a reason that the first 2 vehicles in the flow dont have the error but the last 5 do?

Thanks for this, I didnt think it was done automatically but I wanted to be sure it wasnt happening in the background.   

Does Ventsim consider the impact of the presence of vent ducts on the roadway resistance?   The model im building has 4 large diameter ducts in a very large TBM tunnel, about 26% of the cross sectional area is taken up by ducting.  Will Ventsim adjust the resistance of the tunnel to include the ducts?