Fan Design vs Air Flow

[gstuart]

Sirs,

I am working on a project which is automotive in nature, but it looks like the experts on flow dynamics are in this forum. I am dealing with an automotive alternator cooling fan. I need to show the effect of changing fan diameter or number of fan blades or blade design upon air flow thru the alternator (cfM), with all other variables (pressure, resistance, speed, et all) remaining the same. Are there formulas for these types of calculations? Any help will be greatly appreciated.

Thanks
gstuart

 

[ChasBean1]

G -

fan diameter: Flow2 = Flow1*(Dia2/Dia1)^3

fan blades: this is aerodynamics - I'm not sure if there's a one-fits-all equation for this

fan design: again, no one-fits-all equation

I hope 1/3 of my answer helped. -CB

 

[gstuart]

CB,

Thanks for your response. This has helped.

Greg