PPRuNe Forums - View Single Post - transverse flow vs translation lift - threads merged
Old 4th May 2010, 16:33
  #43 (permalink)  
delta3
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Changing the paradigm ?

Would not it be useful to just talk more about coned rotors as complete systems instead of always going back to all the nuts and bolts it is composed of.

The precession thing has been a very interesting topic on this forum, remember the lively discussions with Lu,
but a rotor is a lot more than that, and going each time through half of an advanced physics course to explain something is imho not always the most productive educational way. It also has a danger that by omitting the other half, wrong conclusions are drawn.

I would follow the suggestion of thecontroller and talk more about aggregate things

I would only go once thru the details of precession and blade speed differences and flap etc to explain the underlying mechanismes, but I would summarize it at an aggregate level as follows

- a rotor blows back, just like an umbrella
- the more its coned the more it blows back
- the higher the speed to more it blows back
- to compensate blow back we put the cyclic more forward, if we don't the nose goes up.
- retreating blade stall makes blow back worse
- coning provokes a blow back delay in the system resulting in a sideways tilting of the rotor that is ironed out by the rigging, so not to worry to much about.

m2c
d3

The student can then forget the details.
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