RCU Forums

RCU Forums (https://www.rcuniverse.com/forum/)
-   Aerodynamics (https://www.rcuniverse.com/forum/aerodynamics-76/)
-   -   Those mall wings on top of fusalage. (https://www.rcuniverse.com/forum/aerodynamics-76/11683985-those-mall-wings-top-fusalage.html)

beachsideflyer 10-22-2020 08:21 PM

Those mall wings on top of fusalage.
 
I have a Volantex 920 3D Trainer that came with a small winglet to be mounted on top of the fusalage. What is the purpose of this and what are they called? The model flys fine without it, but if I were to install it what would the benefit be? My Bravado has one molded in but to tell you the truth, i just donít like the way they look. If installing these on the fusalage what would be the correct angle in relationship to the wing? Thanks for any wisdom shared.

speedracerntrixie 10-23-2020 04:17 AM

The small wings are called Canalizers. Their function is to smooth out the airflow leaving the prop before it hits the tail. This should reduce the amount of required right thrust and increase rudder authority. You should set it to zero degrees and then adjust based on what is observed during knife edge flight. That said, they work best when the airplane is completely dialed in. Your CG and incidence settings need to be spot on before the potential of having them is really noticed. I suggest you get the airplane dialed in really well without it then add it to see if you realize a difference or not.

mithrandir 02-05-2021 07:51 PM


Originally Posted by speedracerntrixie (Post 12640052)
The small wings are called Canalizers. Their function is to smooth out the airflow leaving the prop before it hits the tail. This should reduce the amount of required right thrust and increase rudder authority. You should set it to zero degrees and then adjust based on what is observed during knife edge flight. That said, they work best when the airplane is completely dialed in. Your CG and incidence settings need to be spot on before the potential of having them is really noticed. I suggest you get the airplane dialed in really well without it then add it to see if you realize a difference or not.

has the employment of Contra negated the canalizer? (Seems like a canalizer at worst adds a touch of drag)

speedracerntrixie 02-05-2021 08:07 PM


Originally Posted by mithrandir (Post 12661761)
has the employment of Contra negated the canalizer? (Seems like a canalizer at worst adds a touch of drag)


Mike,
https://cimg6.ibsrv.net/gimg/www.rcu...1544fba5b2.jpg

https://cimg7.ibsrv.net/gimg/www.rcu...b7d726a050.jpg
I would say no. Reason being is that you still have the front prop feeding the rear. Some have experimented with different pitch between the two with the rear prop having more pitch to compensate. The best solution is just go with a biplane. That's what I did when I set out to design my own pattern airplane. There are now 5 of these in existence, the last ARC version I built was setup for a contra. I'm anxiously waiting for it's owner to finish it up and see it in action. For now the single prop versions seem to be doing quite well.

PiccoLino 02-27-2021 11:39 PM

Power to weight ratio and prop size
 
In the last years there has been a significant development in increasing the power of both glow engines and electric motors. This has lead to larger and larger prop size consequently. In the same time, especially in F3A planes, the stabilizer and rudder surface got larger too. These factors combined together can cause a tremendous vortex effect on the tail control surfaces of the plane and torque the fuselage to the point of reducing directionality, hence making the the control inputs response less consistent.
So, why does a small wing attached to the canopy solve the problem? Isn't this small wing hit by the same prop vortex that causes the plane behave erratically?
The canalizer is close to the prop (and to the CG) where the prop air flow speed is much higher than it is by the plane tail surfaces. The higher the prop air flow speed the lower the resulting aerodynamic torque effect because the distance between the vortex waves generated by each revolution of the prop blade are farther one the other. Therefore, given these conditions, the canalizer, rather than twisting and shaking, stabilizes the plane because it (the canalizer) travels through the fluid streamlines when they are still relatively straight.


All times are GMT -8. The time now is 02:15 PM.


Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.