Air Foil Selection

[salman78]

Hello,

I am scratch building a trainer aircraft.

Initial design is that of a high wing configuration, with a 100 cm wingspan.

I can not however decide on what the airfoil should be ?

Should i choose a camber design, or a straigh wing ?

and then what should be power plant characteristics ?

can any one plz point me to the right source ?

[viper1990]

Hi there, um..

I would want you to choose an airfoil which has *camber in it, but having a camber airfoil, your highest and lowest speed might be in a difference of a few km/h. And best flown at an optimum AOA (angle of attack)

Go for a straight wing with aspect ratio of 1:5 -1:7 (pretty much like a cessna wing)


* Any airfoil that is not symmetrical is a cambered airfoil.

Powerplant

Depends on many many many factors. But to make things easy. Keep plane roughly 500grams fully loaded including batt. , Thrust to weight ratio don't have to be 1:1 , you could even fly at 0.5:1 , so a 1000kv 50watts motor spinning a 10inch prop should do the trick. Fix it up with a 20amp esc and with 2s 1000mah batt should give you a nice flight time of 9mins+ (depends on how you throttle)


Go out there and experiment and give it a try! there are thousands of combinations to test out. This figures are just a rough guage.

ok just some pointers.

-Build the wing with washout.

-Washout simply means the wing is built with a twist so that the wing tips are at a lower angle of incidence than the wing root. Washout also limits aerobatic capabilities.

-Sand the leading edge such that it becomes more blunt toward the tip.

-Avoid high aspect ratio wings having a high taper ratio.

-Thicker airfoil though higher drag allows the plane to have higher lift and slower flight
(taken from a website

http://www.airfieldmodels.com/inform...t_airfoils.htm)