Contra / Coaxial rotating Helicopters.

[prashantakerkar]

http://en.wikipedia.org/wiki/Helicopter_rotor

http://en.wikipedia.org/wiki/Contra-rotating

http://en.wikipedia.org/wiki/Contra-rotating_propellers

http://en.wikipedia.org/wiki/Coaxial_rotors

http://www.maxxprod.com/mpi/mpi-266.html‎

http://dspace.mit.edu/handle/1721.1/65309‎

http://dspace.mit.edu/handle/1721.1/61906

http://www.justhelicopters.com/tabid/420/Default.aspx

I want to discuss the advantages and disadvantages of implementing

Contra rotating helicopters design over the conventional main rotor system

in terms of manufacturing cost, efficiency, power, speed etc

The Design complexity will increase if more than two rotors in opposite directions are to be driven in odd and even configuration.

i.e.

3,5,7 etc Odd

4,6,8 etc Even

Increasing the Number of Rotors (3,4,5,6,7,8) can affect the Helicopter speed ?.

Will 3,5,7 etc Odd configuration also work ?

OR

Only 2,4,6,8 etc Even Configuration work ?

Thanks & Regards,

Prashant S Akerkar