Model Airplane Going Around A Central Pylon?

Question

Got this a a school project for first years....

What factors should be included/excluded? (other than normal aerodynamics and airplane construction)

I must add that its not a commercial plane, purely handmade. Its not a toy either, just an engineering project.

All it has to do is to take off on its own power and land when the power is cut.

Just wanted to know some design features and physicalities for the model.

Thanks!

Answer 1

Are you going to fly it around the pylon (RC) or is it going to be tethered to the pylon (Control Line)?

Assuming its going to be tethered:

1.) the tether will have to pivot so as to not wrap itself around the pylon.

2.) power may be an issue if you are going to supply power to the model through the tether as you will need an electrical connection which can spin. If you use an alcohol fueled engine (COX) this is not an issue. But if the model is electrically operated then consideration must be made depending upon where the batteries are located. (onboard or ground based)

3.) Some type of control will be necessary to keep the model flying level and to compensate for a wind gust for example.

(Think about control line model airplanes where two strings are attached to the wing tip and control the elevator)

4.) the connection point of the tether to the model will have to withstand the centripetal forces plus a safety factor.

5.) Again: control line model air planes have some rudder angle applies at a fixed amount to keep the aircraft yawed towards the outside of the circle. You will have to consider which direction the air craft will fly as it will not be easy to change its direction of rotation about the pylon with a fixed rudder angle.

6.) the torque of the engine will cuse the arcraft to roll. This is usually trimmed out with rudder. Torque changes with engine speed and trime changes with air craft speed. The weight of the tether will also make the aircraft have a tendency to roll towards the inside of the circle. Selecting the direction of flight around the circle can aid in over comming roll caused by the tether. The flight direction can be such that the roll caused by engine torque can oppose the roll from tether weight.

Answer 2

Go to any model shop and look at the 'planes constructed

have a look at the kits

have a look at the engines

Radio controlled or Control line?

Control line : a pair of braided steel wires go from the middle of the circle to a bellcrank mounted in the wing root

as the 'plane climbs the bellcrank moves and the push rod moves the elevator (easier if you hold the contol line "handle" as you then can make adjustements)

& get a model makers magazine

Answer 3

Presuming there are controls, the cables must include a swivel system: the continuously turning plane twists the cables one time per rotation. Eventually they will become over-twisted and weak.
The plane can break off the cables an shoot any direction. With children, there should be a barrier completely surrounding the pylon/plane system.