Radiator Size ????

72bluNblu said

Yeah so if you blocked off a radiator the electric fan behind it would definitely lose output, but it wouldn't be because of the rpm the blades were spinning. You might actually get a stall, but that would allow the rpm to remain the same/similar while the output reduced. You're not going to bog an electric motor like that in the real world. The rpm might vary slightly with the air resistance, but the picture you're painting of the motor winding down is not at all accurate.

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Lol, sure whatever you say. The motor rpm will stay the same under full fan load or no fan load. :rolleyes:
If the fan is still spinning flat out, where is all the flow that it should be producing?

"Fan stall occurs as the fan reaches its stable operating range limit. This happens when the pressure rise across a fan increases to the fan’s pressure developing limit and the flow velocity though the fan reduces to the point at which it first falls to zero and then reverses. As the flow through a fan reverses, it separates from the fan blades with the turbulence that occurs with the separated flow buffeting the fan blades. This aerodynamic buffeting induces an increase in unsteady stress within the blades that can result in mechanical failure.
As a fan approaches stall, the separated flow initially occurs with one blade passage. Stall in one blade passage increases the aerodynamic blade loading on the adjacent blade passage, with a consequence that the “stall cell” moves to the next blade passage. This results in a cascading effect as a stall cell jumps from blade passage to blade passage. The shape of and distance between fan blades affect how the stall impacts fan performance with more highly aerodynamic loaded blade designs suffering a more severe reduction in performance during stall than lightly loaded designs."

The fan slows, then goes into stall.
Carry on..enough spoon feeding for today.