Jump to content

Ever piloted a contra rotating helicopter?


Recommended Posts

Hello,

 

I'm currently working on a contra-rotating drone and I am concerned about the rotors being independent of each other versus geared. Particularly regarding the balance of lift, I have briefly researched and came across the idea of a retreating and oncoming blades relative to the direction of flight and headwind. In this case, on a contra-rotating helicopter rotor system, yes, the blades should be "synchronised" in the sense that on one half of the axis parallel to the fuselage of the helicopter where one blade is spinning towards this axis; the other side should also have a blade spinning in the opposite direction also headed towards the fuselage axis. I realize this sounds confusing so a drawing is provided. Although one concern is the height difference as one blade is higher or lower than the other due to the stacking.

 

Regarding the piloting aspect, if the blades are not matched, then do you have to compensate for the imbalance by slightly turning the collective stick one way or yawing... etc... and if the blades are not synchronized eg. mechanically geared to each other then are the conditions of each flight always different although probably neglible?

 

Again I'm mostly talking about the position of each blades and the balance of lift depending on the position of the blades while in flight.

 

post-51632-0-35206600-1438422204_thumb.jpg

  • Like 1
Link to comment
Share on other sites

Helifreak.com might be able to answer your question since it's an RC Heli forum. In the life size coaxial helicopters the blades are geared together, when the pilot wants to yaw the helicopter, more pitch is put into one rotor than the other. In RC coaxial helicopters the blades are usually fixed pitch-meaning to change the lift they make they either slow down or speed up so both rotors are rarely synchronized, they aren't very fast so not really much dissymmetry in lift. Most likely it would lead to a vibration in the mast at higher speeds.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...