design questions
 

I am designing a Skyvan and I'm trying to make it as close to scale as I can. My question is should I use the real airfoil or should I use one that is more suited for RC?

I can't find what airfoil is used on the real plane.


Thanks in advance

Bill

http://www.rcuniverse.com/forum/atta...mentid=2068220

You are always better off using an airfoil that has been proven successful for model airplane use than any of the full size airfoils. The two are unrelated. I have used the NACA 2415, 2417 and 2419 over the years for all of my models. Compufoil software is excellent for this. Dan.

+1. It may look like the real thing, but flies as a model and the conditions inherent to that. Use an airfoil that suits the flight conditions it will see. I also agree on the NACA 24XX series as an excellent choice for much of our model uses.


Mark

It seems that the full size Skyvan uses NACA 63A414
http://m-selig.ae.illinois.edu/ads/aircraft.html

What size is the Skyvan model?

I like the NACA 23XX airfoils vs the 24XX because the high and low point of the airfoil are both at 30%. Makes for ideal D tube construction.
Chuck

@ perttime I have it laid out both at 81" and 90" wing spans.



@ R8893 can you be explain D tube more?

wildwillie,
A "D" tube refers to the end view of an airfoil where the leading edge is sheeted back to the top and bottom spar and there are shear webs between the spars. The outline looks like a stretched out capital letter "D". Pretty common design for models. You'll get the most strength out of a spar if it is at the thickest point of the airfoil.
Chuck

Oh ok, I know what you mean now.

Thanks

Does anyone have a recomendation for power (motor size)? I would like to go with electric.


Bill

It's an easy build and a fun flyer. Two here are electric. 62" span.

Here's my plan.

Very Cool! Rich

It's hard to say because the motors should be selected for the final model power to weight. And that will need to also be based on if you are intending to carry any payloads and how much the gross weight will be with payload.

You'll find that at 55'ish watts per pound that the model will fly in a scale like manner. At 70 watts per lb it'll fly like a WWII fighter or hot modern private plane. More than 80 watts per lb and you're verging on jet fighter territory. At 100 watts per lb it will be very close to unlimited vertical climbing.

Thanks for the guide lines for power, I guess I will just leave space on the firewalls for larger motors if needed. I do plan on using it for payload.


Bill