ORIGINAL: tdstaf
Thanks B Matthews and Alasdair,
The plan is to have a span of about 54.5 with the NACA 24016 as the Root and NACA 24011 as the tip rib as this seems to work well on my Ki 61 of the same size and seems to be the normal practice on its larger counter part.It has worked well on some of my other warbirds using other airfoils.
So I should figure on making it some sort of lifting foreplane with a few degrees of incidence. One question though, the addition of a moving control surface won't affect this? And the other question is should I concider some washout in the main wing or leave it do to the nose stalling first?
Tim
Tim, the Shinden is a very brave undertaking and I admire you for taking up the challenge.
Will your model be electric pusher, EDF, or will you use a micro turbine like Jetcat P-20 or a Kolibri?? Go on, be brave!!!
What about undercarriage? Will you miss it out (likeI would) but then how do you protect the fins under the wing?
From the "Incomplete Guide to airfoil usage...." at
http://agert.homelinux.org/~fredrik/...t.html#canards
the full size Shinden's wing uses
"LB 510215/RAF-30 mod/NACA 23010"
I don't know the LB 510215, but the RAF30 is symmetrical 12.6% thick with max thickness at about 30%. My guess would be that's a root section and the 23010 (probably with 1 or 2 degrees washout) is the tip section.
The Incomplete Guide does not list the canard section
The photo on the Wikipedia page
http://en.wikipedia.org/wiki/Kyushu_J7W makes the wing sections look quite thin. Are you sure you want to go to 16% thick on what should be a low Reynolds Number model? I'd stick to 12% at the root and 9 or 10% at the tip myself. And I'd be tempted to 1 degree, possibly 2 degrees washout.
On my club's website
http://www20.brinkster.com/gvmac/ look on "Alasdair's Section" and you will find a Tail Lift spreadsheet that runs on Excel. Right click, Save as, and open it in Excel, and on the second tab at the bottom you will find that it caters for canards.
In the grey shaded area you change all the numbers in
redto suit your model (numbers in black self calculate).
Using the gross foreplane area will give you a rough working CG, but try changing to the net area for a better idea of the foreplane lift coefficient for a range of overall aircraft Cl values (0 to 1.2 is a valid range for your model). At high speed you should get overall Cl 0.1 (jet) or 0.2 (E-prop) and the wing will stall in the 1.0 to 1.2 region.
[The nose area (difference between net and gross foreplane) helps destabilise the aircraft but doesn't help lift the nose up.]
Putting in rough figures from the scale drawing in BMathews' link makes me think your foreplane will need a Clf at high speed of 0.2 (jet) or 0.3 (prop). That implies a 2% cambered section with chordline at zero or +1.
BMathews' suggestion of NACA2410 (or my idea of a Clark Y thinned to 9% with 2.7% camber, and a flat bottom) would be good with the chordline at +1 or +2 (flat bottom at zero to wing).
If the top speed is high enough you might need a touch of down trim (up elevator) but it should be perfect in a fast cruise and keep the nose up long enough on landing, but at that low Reynolds number it will still stall before the wing.