![]() ![]() Here, more importance was given to maximise the laminar flow on the airfoil. NACA 6 digit series : These are also called laminar flow airfoils. For the above airfoil, maximum thickness of the airfoil is 0.12c The last two digit gives the maximum thickness in hundredths of chord.For this airfoil, location of maximum camber from the leading edge of the airfoil along chord is (30/2 = 15,= 15c/100=0.15c) The next two digit when divided by 2 gives the location of maximum camber from the leading edge of the airfoil in hundredths of chord.For this airfoil, design lift coefficient is (2 x 3/2=3, 3/10=0.3). The first digit when multiplied by 3/2, gives the design lift coefficient in tenths.NACA 5 digit series : Here, the first digit gives the design lift coefficient, second digit gives the location of maximum camber, and last two digit gives the maximum thickness of the airfoil. For the above NACA airfoil, maximum thickness of the airfoil is 0.12c Last two digit gives maximum thickness of the airfoil in hundredths of chord.For the above NACA airfoil, distance of the maximum camber from the leading edge along the chord of the airfoil is 0.4c Second digit is the distance of the maximum camber from the leading edge of the airfoil in tenths of chord.First digit, 2, describes the maximum camber in hundredth of chord.NACA 4 digit series : Here, maximum camber, distance of the maximum camber and maximum thickness is defined in terms of the chord ‘c’. The shape of the airfoil can be described using the of digits which is followed by the word NACA. It initially developed airfoil system which was numbered, giving a numerical designation to each airfoil. NACA is National Advisory Committee for Aeronautics. Thickness : It varies along the chord of the airfoil. it is the maximum distance which is measured perpendicular to the chord line between the mean camber line and the chord line. Chord length or chord is the precise distance from the leading to the trailing edge of the airfoil.Ĭamber : It is a measure of curvature of the airfoil. It is also the point of maximum curvature at the rear end of the airfoil.Ĭhord line : It is a straight line which connects the leading and trailing edge of the airfoil. ![]() Trailing edge: It is the point which is located at the trailing edge of the airfoil and is the most rearward point of the mean camber line. It has a maximum curvature or minimum radius at front of the airfoil. Leading edge :Leading edge is the point which is at the front of airfoil and it is the most forward point of the mean camber line. It intersects the chord line at the leading and trailing edge of the airfoil, and it can curve above or below the chord line. You can read further on airfoil aerodynamics in Part 4 of the Fundamentals of Aircraft Design Series.Mean camber line : It is an imaginary line which is halfway between the upper surface and the lower surface of the airfoil. Highly cambered airfoils produce more lift than lesser cambered airfoils, and an airfoil that has no camber is symmetrical upper and lower surface. ![]() The camber line is a line drawn equidistant between the upper and lower surface at all points along the chord. Camber is generally introduced to an airfoil to increase its maximum lift coefficient, which in turn decreases the stall speed of the aircraft. The final design parameter camber is a measure of the asymmetry between the upper and lower surface. This means that the thickest section has a height equal to 12% of the total chord. The airfoil plotted above has a thickness-to-chord ratio of 12%. The thickness of the airfoil is a very important design parameter and as always expressed as a percentage of the total chord. This often varies down the span of the wing as the wing tapers from the root to the tip. The length of the airfoil from leading to trailing edge is known as the airfoil chord. The airfoil upper and lower surfaces meet at the leading and trailing edges. The forward section of the airfoil is named the leading edge and the rear the trailing edge. The image below of a cross-section through a typical wing, shows a number of fundamental definitions associated with airfoil (aerofoil) nomenclature.
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