![naca 2412 airfoil naca 2412 airfoil](http://selever.freeshell.org/pictures/aerospace/NACA2412_true-pressdist0.jpg)
People don't generally seem to end up doing much less tunnel work, or saving much development money, because the CFD studies tend to drive additional trade studies which ultimately end up in the tunnel.
![naca 2412 airfoil naca 2412 airfoil](https://i.ytimg.com/vi/2NQU6cvIUeE/maxresdefault.jpg)
It can be very helpful, but understanding the limits of validity can be a major job, and gridding can be even less fun than lofting. Often it's used as an advertising tool to convince managers that work is justifiable. Compound curvature in production airliner wings in Europe only started with the A310, which is pretty recent really.ĬFD is an extremely deep rabbit hole & although all sorts of claims are made about it, it's not magic. you don't have to make everything straight-ruled these days, but it can still be expensive. Some people claim to like Catia, but I suspect that this is Stockholm syndrome.ĬNC machining can reduce lofting constraints, so e.g. Lofting is still a royal pain, though some tools are better than others (Open VSP is great). It's just not as much of an issue anymore with CFD and CNC But the price of that performance is risk (or risk reduction efforts, depending upon your preference). There are better four digit sections, the six digit sections are in a different league, and bespoke sections tailored for the application are yet another league above in performance terms. The fact that it was possible for people displaying this rather Luddite attitude aerodynamics to be successful illustrates the over-riding difficulties of manufacturing tolerance & weight control in the golden age (& indeed at the low performance end of GA today). Its widespread popularity serves to highlight the people who basically don't care about aerofoil sections beyond a certain point (the 80-20 rule, or nobody got fired for buying IBM brigade). What seems to have happened is that people who had reasonably successful legacy aeroplanes based upon Clark Y or similar sections switched to NACA 2412 because the it's basically the same thing (low risk) but with a neat numerical definition, which makes it easier to generate accurate drawings & loft the wing shape correctly. The four digit sections really bridge the gap between the aerodynamics of wing sections being an art and a science, because they allow a somewhat rational definition & exploration of a design space, but had an experimental-rather than theoretical-starting point. In fact, the four digit sections use a thickness distribution based upon Clark Y and Göttingen 398 (1919), because they are similar & were known to work reasonably well. NACA 2412 is basically a slightly sexier version of Clark Y (1922 vintage).