Posted by anaximander on December 18, 2009 at 5:51am
I've been playing around with airframe designs for my UAV project, and I thought I'd see what you guys thought. I'm building the whole system from the ground up for a semi-uni-related project, so that rules out buying an RC plane to convert, but it does open up the possibility of using the uni workshops to build something impressive. Looking around on this site and a couple of others, I've come to the conclusion that a twin-boom high-wing configuration would be the best, as I suspected. In the interest of clean airflow, unobstructed camera views and centre of mass considerations, I'm planning to go with a pusher layout, and I'm leaning towards a ducted fan although it's quite possible I'll give up on that and go with a prop. So, what do you guys think of this concept drawing?The wing looks rather fat; I did the front view last and didn't realise how chunky it was. Also, I realised after I'd finished that the wing needs a greater setting angle than that to give it a decent angle of attack on takeoff, but that can be easily edited later. I'm just mocking it up in 3D so I can calculate a few basic details (if I can work out how...)
The plane looks pretty clean . I'm also looking of building some thing similar, but just sketches only. How about your take off and landing? Like to see some dimension, cause still new in building rc planes......
The evidence points to ducts being inefficient - ask around those who fly ducters and conventional propped aircraft and they will usually say 4-5mins flight time at high speed compared with 10-20mins with prop. The ducter is small diameter and hence cross sectional area but high eflux velocity. This is not what you want for average flight speeds - large diameter high pitched props are the best but not always practical.
Quite a number of designs use a conventional prop but then use V-shaped split tail arrangement to lift the control surfaces out of the turbulent air coming off prop.
As far as noise is concerned ducters are very noisey compared with a conventional prop.
Replies
Quite a number of designs use a conventional prop but then use V-shaped split tail arrangement to lift the control surfaces out of the turbulent air coming off prop.
As far as noise is concerned ducters are very noisey compared with a conventional prop.
Good luck, Peter