Ariane 5 : new wings / which profile ?

[Derek Belgium]

I bought a time ago the Ariane 5 produced by Aviamodelli/Krick. As the wings are much too heavy, I decided to make new ones. My question is what profile would be best suited for this model. I was thinking of a SD7080 as the wings are rather large for a motor-gliders ( on electric - Drive 502 ). I was thinking of a chord of 250 to 150 mm. What do you think ?
The present wings are NACA23015/23012, very thick and heavy. Another profile I was thinking about is the Spica.
As I bouth have PS15 and heavier Styrodur ( 35kg/m3), I'm also wondering which styro I should use best. The core will be covered with 1.5mm balsa and 80gr glass between the core and the balsa.
ALL opinions are welcome ! Thanks a lot.
Greetings from Belgium.

[Ollie]

"The present wings are NACA23015/23012, very thick and heavy."
What is the weight of the present wings?
How much lighter than you want the new wings?
How do you want the new wings strength?
What wing span that you want? ( No Google info on Ariane 5 and Aviamodelli/Krick)
What is present model with total weight?
What do you want the new stalling air speed?
How do you want to glide at new model at highest speed?

[Derek Belgium]

Thanks for your answer. You can find the information on the Ariane 5 when you search for Aviomodelli ( and not Aviamodelli , my mistake ). In fact I strengthened the wings with carbon tubes as I read here in the Forum that the wings might break. I prefer a rather calm model, no speed-model. The wingspan is around 3m with 56m2 wingsurface. I stopped constructing the present wings as they were too heavy anyhow. In fact it's a motor-soarer, Grob-Dimona alike. It can be installed with a 3-6cc motor but I plan to install a Drive 502 Kontronik with 2P3S Konions or 2P4S. This should give 350-400W. In the normal motor-version it would weight 3-3.2 kg. I think I could keep the same weight. The question is whether the SD3070 is the best profile for this model. This profile is more for pure gliders, no ? I want to combine the feeling of flying a soarer but with the fuselage of the Ariane ( that fuselage is also rather short, perhaps too short ). As the fuselage is made of Duraflex (hmmm), I had to strengthen it as well with Kevlar from the inside.
Greetings

[Ollie]

"I prefer a rather calm model, no speed-model."

Starting with the stock model, it has too much wing loading for your purpose. Then you increased the weight of the wings with carbon tubes increasing the wing loading. Then you propose to increase the weight with elecric power which has even more increased wing loading. You are not going in the direction for your model purpose.

So far you have not given enough data to answer me.

What is the itemised weight of your fuselage, radio, motor, prop, ECS, battery, radio and tail?

What is the old wing modified at measured weight?

From real weights we can calculate the stalling speed with the old airfoil. Then you can pick the new stalling speed objective with lower wing loading and a new airfoil, including airfoil thickness and maximum lift coefficient. The thickness will depend on the stiffness, strength and weight for the wing structure. You might have to reduce fuselage and power equipment weight to reduce wing loading for your purpose.

[Derek Belgium]

Indeed Ollie, I didn't give you enough information. So here we go.

URL : www.internet-rc.com/ar5motglidby.html showing the model

I just took the weight of the components :
Fuselage 610 gr 50.00"
wings 1100 gr 114.90"
landinggear 140 gr
balsa 140 gr
stabilizer 55 gr
canopy 110 gr !
wingjoiner 80 gr
small items
+tailwheel 110 gr

TOTAL 2325 gr for a wingsurface of 871 sq.inch
The strengthening of the fuselage with kevlar and the wings with carbon tubes added perhaps 200gr that are included in the 2325gr

My planning would be to keep the 115" for the wings but with a much bigger area and lower weight. The profile is old-fashioned, very thick and too tapered. I would change the profile to a soarer-profile like the SD7080 and make a new fuselage instead of the Duraflex one. I could use the present fuselage as a mould but plan to make the fuselage a bit longer.

Also the landinggear and the canopy I'm planning to change, too heavy.

Weight of the electronic components would be :
RC-equipment : 150 gr
Motor : Kontronik Fun 500-27 5.2:1 + Smile controller 45A 6-18 weight 230gr
Alternative motor : Plettenberg HP 220/20 A3 "S" P6 with 1:4 reduction

The Aeronaut Grob G109 is quite similar : 2.777mm Fuselage : 1.333mm
but much lighter. With the Actro 12-6 motor it only weights 3000 gr.

Battery : 12 to 14 V LiPo or NC

Rgds,
Dirk

[Ollie]

"My planning would be to keep the 115" for the wings but with a much bigger area and lower weight. The profile is old-fashioned, very thick and too tapered. I would change the profile to a soarer-profile like the SD7080 and make a new fuselage instead of the Duraflex one. I could use the present fuselage as a mould but plan to make the fuselage a bit longer."

If you increase the wing area you must change the tail area for stability and control. You must change the whole plane design. You can't keep any parts.

See:
http://www.airplane-model.com/graphite2.html
Or
http://www.airplane-model.com/organic2000sp.htm
Organic 2500

These are best quality designs for your purpose.

You can't make a pig skin into a silk purse.