Hi everybody,I have here a new concept I developed myself a long time back,when I was in high school, for the elimination of tail rotor in a single main rotor helicopter and replacing it with a vertically mounted lift producing surface...The advantage of this setup is that we've all the power,excluding the losses due to transmission,going to the main rotor...
Currently,I am working on this design concept but haven't concluded anything yet..Hope that it will prove applicable in the real world..One thing I can say for sure is that it'll work in a hover mode where we'll have high velocity downwash from the main rotor acting on the surface to produce anti-torque effect...As the heli gradually advances into forward flight,we'll have to depend on the increased mass of air,rather than high velocity downwash, for the torque effect to sustain...One major problem facing this concept is that in forward flight,there will be two different types of airflow acting on the surface...One will be the downwash from the main rotor acting perpendicular to the leading edge of the surface and the other the aircraft relative wind acting parallel to it...I've attached a drawing of the concept in this post...
Give me some ideas...
tsheten8 wrote:I have here a new concept I developed myself a long time back
I have here a new concept I developed myself a long time back
Would this be an example of contradiction?
In all seriousness, this is a fascinating concept. Though, issues with stability and efficiency come to mind when I think of utilizing the configuration in forward flight.
Wish I had a better engineering point of view so I could give more helpful feedback.
Best of luck...
Από κάθε γενιά μεταξύ κάθε έθνος ανθρώπων, να θυμάστε νεκρών στρατιωτών μας.”
Here are some images of hyperfly Dave mentioned about...It's basically a single bladed rotor helo with a counter weight on the opposite side the hub...In my concept,I have more than a blade...
Tp be honest this seems more approprtiate in Builders section, that is if you plan to build concept one day.
Sorry to dissapoint You tsheten8, but Hafner experimented with this concept back in 1932. It was Hafner Revoplane RII.
"Feasible", maybe not. Here's some info I found here:
Outside of some somewhat brief tethered flight, the design was not successful in achieving free flight.
I'm wondering if there would be pitch-up problems associated with it? The downwash impinging on the tail would tend to push it down and therefore lift the nose up, yes? You might be able to counter that by moving the center of gravity, I suppose. Perhaps if the tail were shaped like an airfoil with a control surface on it, it could minimize the pitching effects and better control yaw.
EDIT: Nevermind. I forgot about Newton's action-reaction law. It wouldn't make it pitch down the way I thought.
I had my own idea once for torque control; channel the exhaust thrust produced by the turbines in the turboshafts down a duct that leads to the tip of the tail. Then use a vectoring nozzle to direct the thrust in the appropriate direction to counter torque. Vary the angle of deflection to produce larger moments or smaller moments.
I meant that the tail would probably be more efficient if it were actually shaped like an airfoil relative to the direction of the rotor downwash. That way you'd have less boundary layer seperation than if the tail were simply a flat plate canted at an angle. The "elevator" could control the amount of deflection and therefore the amount of force produced by the tail in yaw.
Interesting!!! Can You give me a link to this research?
This picture is from 1999 russian magazine, they stated that tail area must be 17...21% of main rotor area. This system could suffer from wind gusts and may have problems in ground effect.
Russians took it one step further.
An other interesting forum on this topic: