PPRuNe Forums - View Single Post - Multiple rotor vs single rotor efficiency
Old 18th December 2007 | 20:51
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Dave_Jackson
 
Joined: Apr 2003
Posts: 1,635
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From: Vancouver, BC, Canada
Nick, I agree with what you are saying, however, for the fun of technical discussions, the following expansion of your two points is raised; in reverse order.


2) It is appearing that future advancements in electromechanical drives will present new opportunities and require some rethinking. This is one example of electric cars that have a separate motor in each of the four wheels.

You have noted in the past that Igor waited until the efficiencies of engines reached a favorable level before he went back to helicopters. This same situation is probably repeating today as people try to apply electric drives to the inefficient rotorcraft.


1) 'Disk loading' is a convenient way of evaluating thrust/weight considerations. However, I think that it looses much of it validity when evaluating comparative rotor configurations.
This has to do with the fact that 50% of a rotor's thrust is coming from the outer 25% of it's disk area. IMHO, one of the strong arguments for the Interleaving Configuration is its distribution of the thrust about the total disk area.
A bunch of babbling on this subject.


Dave

Last edited by Dave_Jackson; 21st December 2007 at 04:13. Reason: Spelling
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