Posted by Michael V |
May 20, 2014 @ 10:13 PM | 2,408 Views
Okay guys, after reading much stuff left and right on how to stiffen a wing with carbon rods, or slats, where, etc.. I realized that even if I had a general grasp of the principle, I didn't have more exact data. So I looked it up and calculated what I could.
So here it is, as is, with no guarantee whatsoever.
There is a big document explaining in details (I hope) and the two main tables that derived from the calculations.
There are many more factors involved (mostly geometry) and especially in composite material (skins, skin adhesion, etc..) but this is a fair starting point IMO.
Have fun and make planes! (and feel free to comment critic, add, etc..)
Further study, comparison of horizontal versus vertical stiffening members.
For example carbon fiber slats in foam wing
Posted by Michael V |
Sep 18, 2013 @ 07:08 PM | 3,291 Views
Some time ago I started a new project, ambitious but that's how I like them.
I wanted to design a slope "jet". Before I tackled my favorite jets (F16, F14, F18E, some are already in progress, design stage) I stumbled upon the SU37 thread as a parkjet so it inspired me to design a SU 27 (no canards yet, that may become a later project, baby steps see)
So here I went and designed from scratch.
I used MPF (Model Plane Foam) as it is the best medium out there in my opinion.
The basic design objectives were:
1 - Light plane
2 - Enough lift so that it would fly correctly
3 - Simplified overall shape, yet good enough to look good and "scale"
4 - Smart enough aero design in the hope that it would perform some "post stall" maneuvers although I knew that was borderline impossible considering the format (light, lack of engines, has to be stable (CG forward of AC))
4- Test bed for some ideas in design (direct drive control surfaces)
and hopefully it would fly well and be fun to fly too.
So a list of design choices were made (to be tested):
- Foam, painted in acrylic and covered with laminating film
- Some LE reinforcement, 3/16 wood round
- Direct drive tailerons, no other surfaces for the time being
- Airbrake, for fun, and also as a access hatch for the electronic, more on that later
- Subsonic wings, based on KFm2 airfoil for gentle stall characteristics and ease of building. No flat plank here, this thing needs to soar.
- Lifting "engine...Continue Reading