Hi there.

I would like to know what does the "T" modifier in NACA airfoil series really means, as in NACA 0012T.

Graphically speaking, it looks similar to some 4 digit series with modifier numbers (i.e. 0012-43), but I can't find the explanation.

It seems that the major change is in the Leading Edge Radius.

I am interesting to use a "T" modifier in a 0019 airfoil, but I can't understand how.

Thanks and regards

I have found a quick mention in Abbot and Doenhoff , pg 116,

"Some early modifications of the NACA four digit series wing sections included thinner nosed and blunter nosed sections which were denoted by the suffixes T and B respectively ."

It ends the paragraph with , " These modified sections have been little used and will not be disscussed further"
Hence there is no data for them in the rest of the book


Nick

Nick, thanks.

Nose looks thinner, really. It is much obvious at thicker airfoils, like NACA 0018T.

I don't know if "T" airfoils works better, I tried to compare them with Profili, but I am no good at reading the Cd graphics [>:]

"T" looks nicer, and seems similar at the ones Joe Bridi used for the RCM Advanced Trainer. [8D]

Thanks again and regards

By thinner, do you mean more pointed? The Ultra Sports' airfoils were even more pointy than some of Bridi's. I'm basing this on comparisons I've made with RCM plans, the kits may have differed.

Yes, I mean more pointed.

I don't know why Mr Bridi uses those profiles (I think the ones used in the Sun Fli and Kaos are also more pointed), but I guess it is because in thick airfoils, like 0018 or 0019, I would need to thin the nose in order to simplify the LE construction.

NACA 0018-23 looks similar, but ticker towards the TE.

If I remember well, you were asking for specific profiles in other post, and I suggested you to see those "T" profiles....


Nick: thanks for the reference in Abbott and Von Doenhoff, I got it right in front of me, but I wouldn't find the information without you help.