The tricky question are:
- type/series of wing profile used (claimed to be of laminar flow)
- wing thickness-to-chord ratio?
Some data can be accesed via convoluted channels, like this pic attached. The wing profile details might be the two rows I've marked with joint red '?'.
Many thanks, Shinpachi
By chance, could it be that you have some extra information about the Raiden's wing, I'm very interested in thickness-to-chord ratio.
You are welcome, tomo.
I'm now researching Professor Ichiro Tani's reports as he suggested his laminar airfoils to Japanese for the first time in the 1930s.
Give me some time. Thanks.
Following is my estimation with apology if wrong.
Professor Tani seems having been thinking that symmetrical wing would be the best for the laminar flow airfoil.
No exact data for the wing of J2M Raiden but some wing diagrams in the J2M manual also show such symmetrical shape.
The LB24 airfoil which was introduced to Kawasaki Aircraft in 1941 by Tani also shows such design.
Most thickness is located at 50% of the chord.
I think the wing thickness-to-chord ratio is 1:10
Yes, there are, tomo.
The table comes from Tani's report which summarizes his job for the military but he does not seem being allowed to clarify which airfoil for which airframe as of 1940. Famous LB-winged planes are Ki-78(Kawasaki), N1K1(Kawanishi), E15K1(Kawanishi) and R1Y(Kugisho). There may be more like J2M, P1Y and D4Y as the navy recommended strongly.
Not sure whether this can help us, but anyway. I've took a peek in the N1K2 manual available on this site (link), and tried to measure it via pdf tool. The t-t-c looks to be 15%.
The correspondence between the image and the table data for LB 55 seems to be appropriate taking into account the precision of drawing tools. The angle of attack is displayed incorrectly in the image (3.3° instead of 2.0°).
I digitized the airfoils shown in the figure in post #16 and then loaded each into Xfoil. Both have a little camber, but if this is removed, the thickness forms of both match the LB56 (scaled to the appropriate thickness).
Working with NACA TM-1351, I find that the likely designation of the J2M airfoils are LB560715 (0.787% camber, 14.61% thick) at the root and LB561114 (1.135% camber, 13.70% thick) at the tip