Airfoiled Blades and Centrifugal Fans

I think you need to get a copy of "Turbines, Compressors and Fans" by J. Yahya. Mcgaw hill publisers (India) All is explained therein. The maths isn't too hard and there is enough text to work out the points without it. He covers pretty much every aspect and type of turbo machine. I might have miss spelt his name, I'll check when I get home.

M

sorry I can't sign in I'm using a 'Secure' Computer which won't allow it.

Think of a propeller. Basically, an airfioled fan blade is a propeller. it is made to produce forword or reverse thrust. The bigger the thrust is, the bigger amount of air will be "sucked" by the propeller. This amount of air, will be pushed away from the propeller's back. and if you want this air to be pushed away from the front, just reverse the pitch. Conclusion: you want an efficient fan, choose the best airfoil you find.

Wangito

Just the other day I was looking at a "squirrel cage" fan and was wondering about the need for camber in the blades.

The blades of this fan are thin sheet metal, so besides a possible aerodynamic advantage the camber will add considerable stiffness to the blades, like with a tape measure.

I guess I could determine the effectiveness of the camber on fan performance by measuring airflow with the fan, then reversing it's direction of rotation and measuring again. But that's a lot of work and I'm tired.