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Old 13th Mar 2013, 05:52
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shiftyone55
 
Join Date: Mar 2013
Location: USA
Age: 35
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Aerodynamics Question

Hey all,

First of all the diagrams of the things I'm trying to explain are as follows





I have a question, I'm in the Blackhawk course for the Army. In our aerodynamics manual it states that the AoA (angle of attack) is the same for IGE and OGE conditions "...Induced flow velocity is increased causing a decrease in AOA. A higher blade pitch angle is required to maintain the same AOA as in IGE hover."

I have a problem fully accepting this notion because the as the AoA increases this will shift the Total aerodynamic force (TAF) to the rear and if the lift vector were to remain the same, the lift in the positive Y direction would be reduced. The only thing I can think of that would counteract this would be an increased lift from the increased overall velocity of the resultant relative wind caused by the increased induced flow.

I know this may be hard to read but any insight is really appreciated. Or if you know a reference that confirms or denies this that is really what I'm looking for. I looked through several aerodynamics manuals of other services and the FAA and none specifically mention this specific. Basically I'm looking for a source that doesn't reference the 1-203 Fundamentals of flight manual

Thanks for your time!!
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