So, the description of the NACA 5-digit foils was flat wrong and at odds with the cited reference (which was, correctly, the canonical source). Is there a problem with them or is it just equivalent calculationĀ ?
The given formulas seem not to be correct, compared to theseĀ . Preceding unsigned comment added by 66.166.4.118 ( talk) 18:37, 6 November 2013 (UTC) Formulas Also it'd be nice if the number of NACA profile for the red lined section was called out. You only need *one* clarifying chord, camber etc. Should not the conditions for the 5-digit camber line use m rather than p, since m is the chordwise location at which the leading and trailing curves intersect? Using the trailing (linear) curve for an x value between p and m will result in a slight discontinuity of the surface curvature. contribs) 03:31, 4 February 2011 (UTC) Equation for 5-Digit camber line.Preceding unsigned comment added by Sverek ( talk Standards are technical by definition, and the correct equation should be stated.
#AIRFOIL DIAGRAMS HOW TO#
It is stated in the article that equation is not closed, and how to modify it to suite your needs if you want to close it. How people solve the problem with the closing of the trailing edge is very personal choice, some people modify the equation, some people put an extra element behind the trailing edge. To ensure a closed airfoil it is only necessary to make sure the coefficients sum to zero. Many times you see the x^4 coefficient modified instead. However, the choice made by the Wiki author to use the x^3 term to close it is arbitrary, I think. However, most people these days are probably using these airfoil equations for computational studies, where it is best to close the airfoil.
#AIRFOIL DIAGRAMS SERIES#
The fact of the matter is, the NACA 4-digit series was empirically derived from real airfoils, none of which actually have a zero-thickness trailing edge (obviously). It is probably best to actually mention this in the article, I guess, though perhaps that is getting too technical. Interestingly, the NACA 4-digit series as specified in the referenced source has a finite thickness at the trailing edge: the original equation here on Wikipedia was modified to create a zero-thickness TE. (Apologies if this is in the wrong place or whatever - wikipedia newbie) -Preceding unsigned comment added by 150.214.142.101 ( talk) 10:18, 19 April 2010 (UTC)
The third coefficient, 0.3537, seems to be wrong. pfctdayelise ( talk) 14:25, 2 August 2008 (UTC) Equation for a symmetrical 4-digit NACA airfoil The German article has good diagrams which would just need the captions translated. 9 7-series and letters for standard profiles.2 Equation for a symmetrical 4-digit NACA airfoil.