Engineering360: "Rethinking the Centrifugal Fan"

"The blades are shallow with a substantial curvature in the direction of rotation that results in a higher blade tip speed than a BC blade."

This doesn't make sense. With the same RPM and the same radius, the blade tip speed would be the same for FC or BC.

Thanks for the comment John and you're right. This could have been clearer. It's the air velocity that is different.

V1 = tip (tangential) velocity; V2 = radial velocity; R = resultant velocity

FC = resultant air velocity “R” leaving the blade is greater than the blade tip velocity

BC = resultant air velocity “R” leaving the blade is less than the blade tip velocity

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