This document summarizes the key geometric and aerodynamic characteristics of airfoils. It discusses airfoil shape parameters like chord length, camber, and thickness. It also describes different common airfoil types and series developed by organizations like NACA. The document explains lift, drag, and moment coefficients and how they relate to angle of attack, Reynolds number, and Mach number. It discusses important aerodynamic concepts like flow separation, stall, and dynamic similarity which allows wind tunnel testing of scaled models.

1. Chapter 5 Airfoils Prof. Galal Bahgat Salem Aerospace Dept. Cairo University

3. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University

4. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University Airfoil geometric characteristics include: 1- Mean camber line : The locus of points halfway between the upper and lower surfaces as measured perpendicular to the mean camber line. 2- Leading & trailing edges: The most forward and rearward points of the mean camber line. 3- Chord line: The straight line connecting the leading and trailing edges.

9. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University

12. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University Conventional Airfoil Pressure distribution On upper surface

13. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University Laminar Airfoil Pressure distribution On upper surface

19. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University M c/4 is function of angle of attack α , i.e. its value depends on α .

23. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University L α (V ∞ , ρ ∞ , µ ∞ , a ∞ , S) = const 1 L V ∞ 2 3 ρ ∞ 4 5 6 L L L L µ ∞ a ∞ S Therefore, 6 experiments are required for each dependent variable. ( α , ρ ∞ , µ ∞ , a ∞ , S) ( α , V ∞ , µ ∞ , a ∞ , S) = const = const ( α , V ∞ , ρ ∞ , a ∞ , S) = const ( α , V ∞ , ρ ∞ , µ ∞ , S) = const ( α , V ∞ , ρ ∞ , µ ∞ , a ∞ ) = const

28. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University

31. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University c d and c m,ac versus c l NACA 2415 Mach number is not included

32. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University Mach number is not included

33. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University Mach number is not included

38. Prof. Galal Bahgat Salem Aerospace Dept. Cairo University