Re: does 7 blade fan reduce hp over 5 blade
It's basic aerodynamics: If the fan is moving more air, it will absorb more power. This is not necessarily a direct function of the number of blades. It would take into account the airfoil of the blades, the length of same, and especially the pitch of the blades. The closer that the blades fit the shroud, the more efficient the fan. Although not likely to be an issue with relatively small automotive cooling fans, excessive blade tip velocity can become an issue at higher fan speeds. Even something as simple as a fan can take a bit of engineering.
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