WattFlyer RC Electric Flight Forums - Discuss radio control eflight - View Single Post - What the heck is wrong with my giant wing?
Old 06-01-2016, 07:47 AM
  #16  
JetPlaneFlyer
Super Contributor
 
JetPlaneFlyer's Avatar
 
Join Date: Mar 2009
Location: Aberdeen, Scotland
Posts: 6,120
Default

Originally Posted by mclarkson View Post
So ... here's what I don't understand. (This may sound confrontational, but it's not.)

Why do I have four different wings using that same airfoil that fly just fine? One of them is among my best-flying planes ever.

What about the millions of flying wings out there using something like an Armin wing? Or the Flite Test Versa flying wing? Really simple sorta-airfoils that seem to work just fine.
  1. The airfoil on this one looks very thick with the maximum thickness and camber placed well back. With a flat bottom the thicker airfoil means more camber which for a flying wing is bad, as is having maximum camber toward the back.
  2. Second you only have moderate sweep and you don't use any twist, some of these other designs may use more sweep and/or twist? With lots of sweep and twist you can make a flat bottom airfoil work reasonably ok.
  3. Third size matters. Due to Reynolds Number effects what you 'get away with' on a small wing might not work the same on a big one.
I know that tailless airfoils like the MH-60 are not as easy to build but you will be rewarded with a much better flying wing, that's 100% guaranteed. You can simplify the airfoil shape with minimal impact on performance by keeping the same mean camber line and tweaking thickness so that the top-rear part of the airfoil becomes a flat surface, then you can build the wing inverted.

I can draw up a simplified airfoil if you like?
JetPlaneFlyer is offline  
 
Page generated in 0.03217 seconds with 10 queries