what software is best and easiest to do this:
 

hello

I am having this prototype consisting of a centrifugal fan inside apipe were all the incoming and existing air having teh same orifice.. in teh end of that pie there is an airfoil were the laminar air should flow smoothly in a swirling manner.. determing parameters for this stuff would be much simpler with a software but question is which one fits me best?

kalle