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Old 06-19-2020, 08:49 AM
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mbauer mbauer is offline
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Quote:
Originally Posted by maurice View Post
The RQ170 seems likely to use a symetric airfoil (same upper and lower curves) on the outer panels but by the time it gets to the centreline the upper surface curves a great deal more than the lower.
At least one person seems to agree with this - see picture 21/23 at
https://www.pond5.com/3d-models/item...q-170-sentinel

Off now to the somewhat ancient NACA 4 digit symetrics at
NACA 4 digit airfoil generator (NACA 0012 AIRFOIL)
which should be good enough for the RQ170.
(that site also gives links to many other airfoils)

How about 6% thickness at the tip with 12% at the panel joint, and at the centreline combine the lower curve of the 12% with the the upper curve of perhaps the 18%.

Cut out enough of these sections to make up 2 handed inner and 2 outer panels from card, and decide the spar shapes and dihedral required so that the sections can be set up vertically relative to each other and also brace them to be parallel horizontally

Card Modeling FAQ
is still a worthwhile place and in this case because it includes
Card Modeling FAQ Appendix: Designing Paper Models
and down that page is a section on "Rollation"


As a bit of a slightly off topic aside
The Incomplete Guide to Airfoil Usage
https://m-selig.ae.illinois.edu/ads/aircraft.html
may tell you which airfoil was used on an a particular aircraft and I reckon model designers ought to check whether it does. A web search may then turn up the actual shape - or not
- but certainly not in this case.
Wow, what a great link for the NACA 4. Have all the ones up to the 0024 already plotted. Just looked at a few of the others. Thank you once again. Now have more airfoils to mess with.

Mike
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