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  #16  
Old 09-25-2012, 03:03 PM
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Dave Jackson
 
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Default Just food for thought

Quote:
.... Let's say your flying a a/c with a governor that is going to hold your blade rpm at 500 rpm ....

.... so you have to pull more collective that increases the AOA which again reduces lift, ....
Paul,

You bring up an interesting subject but I suspect that it needs some elaboration.

Maintaining a fixed rotor rpm while experiancing an increased the coning angle will reduce the flat disk area and the sweep area of the coned blades. This will reduce the velocity of the airflow across all the blade elements. As you say, the lift will decrease.

However, perhaps maintaining the power, when increasing the collective, may maintain the lift. The thinking behind this is based on the assumption that 'nature knows best'. An earlier thread Vertical Autorotation was an attempt to try and understand why an autorotating Maple seed has a coning angle of approximate 20-degrees.

Lower coning angles are advantageous for forward flight, but may not necessarily be advantageous for (near) vertical flight.


Dave
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  #17  
Old 11-12-2012, 05:57 PM
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Default Tail rotor Question.

Stan after reading through this post on lateral transverse flow I started poking around the internet for helicopter aerodynamics and came across a book. In it was a discussion about tail rotor efficiency and design.

Lateral flight was discussed on TR efficiency and LTE. So for a CCW Helicopter and the corresponding TR thrust.....that you can get into LTE at high enoughs speeds.

Did you notice any of this during your Transverse Flow Lateral flight Experiment?
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