13/01/2018
Day 2
Aerofoil
Aerofoil Terminology:
1. Aerofoil: A shape capable of producing lift with relatively high efficiency.
2. Chord Line: A straight line joining the centers of curvature of the leading and trailing edges of an aerofoil.
3. Chord: The distance between the leading and trailing edges measured along chord line.
4. Angle of Incidence: The angle between the chord line and the horizontal datum (longitudinal axis ) of the a/c. This angle is fixed for the wing, but may be variable for the tailplane.
5. Mean line or Mean camber line: A line joining the leading and trailing edges of an aerofoil equidistant from the upper and the lower surfaces.
6. Camber: Camber is curvature of aerofoil.
7. Maximum camber: The maximum distance of the mean line from the chord line. Maximum camber is expressed as a percentage of the chord, with its location as a percentage of the chord aft the leading edge. When the camber line lies above the chord line the aerofoil is said to have positive camber, and if the camber line is below the chord line it is said to have negative camber. A symmetrical aerofoil has no camber because the chord line and the camber line are co-incident.
8. Thickness: the thickness of an aerofoil is the distance between its upper and lower surfaces. The thickeness also varies from leading edge to trailing edge. An aerofoil is specified by thickness ratio or thickness chord ratio.
9. Thickness ratio or Thickness-chord ratio: The maximum thickness or depth of an aerofoil section expressed as the percentage of the chord, with its location as a percentage of the chord aft of the leading edge. The thickness and thickness distribution of the aerofoil section have a great influence on its airflow characterstic.
10. Leading Edge Radius: The radius of curvature of the leading edge. The size of the leading edge radius can significantly effect the initial airflow characteristic of the aerofoil section
11. Relative Airflow: If the wind has these three qualities then it is called to be relative airflow.
a. Direction: air parallel to and in opposite direction to the flight path of the a/c .
b. Condition: air close to but unaffected by presence of a/c, its temperature , velocity, and pressure not affected by the passage of a/c.
c. Magnitude: the magnitude of the Relative Air Flow is the TAS.
12. Effective Air Flow: if air does not possess all three of these qualities mentioned above it is referred as Effective Airflow.
13. Total Reaction: The resultant of all aerodynamic forces acting on the aerofoil section.
14. Centre of Pressure: The point on the chord line , through which lift is considered to be acting.
15. Lift: The aerodynamic force which acts at 90* to the Relative Air Flow.
16. Drag: The aerodynamic force which acts parallel to and in same direction of as of Relative Air Flow but in opposite direction of flight path.
17. Angle of attack/Aerodynamic Incidence: The angle between the chord line and Relative Airflow.
18. Effective angle of Attack: The angle between the chord line and the effective airflow is referred as the Effective Angle of Attack.
Aerofoil
Aerofoil Terminology:
1. Aerofoil: A shape capable of producing lift with relatively high efficiency.
2. Chord Line: A straight line joining the centers of curvature of the leading and trailing edges of an aerofoil.
3. Chord: The distance between the leading and trailing edges measured along chord line.
4. Angle of Incidence: The angle between the chord line and the horizontal datum (longitudinal axis ) of the a/c. This angle is fixed for the wing, but may be variable for the tailplane.
5. Mean line or Mean camber line: A line joining the leading and trailing edges of an aerofoil equidistant from the upper and the lower surfaces.
6. Camber: Camber is curvature of aerofoil.
7. Maximum camber: The maximum distance of the mean line from the chord line. Maximum camber is expressed as a percentage of the chord, with its location as a percentage of the chord aft the leading edge. When the camber line lies above the chord line the aerofoil is said to have positive camber, and if the camber line is below the chord line it is said to have negative camber. A symmetrical aerofoil has no camber because the chord line and the camber line are co-incident.
8. Thickness: the thickness of an aerofoil is the distance between its upper and lower surfaces. The thickeness also varies from leading edge to trailing edge. An aerofoil is specified by thickness ratio or thickness chord ratio.
9. Thickness ratio or Thickness-chord ratio: The maximum thickness or depth of an aerofoil section expressed as the percentage of the chord, with its location as a percentage of the chord aft of the leading edge. The thickness and thickness distribution of the aerofoil section have a great influence on its airflow characterstic.
10. Leading Edge Radius: The radius of curvature of the leading edge. The size of the leading edge radius can significantly effect the initial airflow characteristic of the aerofoil section
11. Relative Airflow: If the wind has these three qualities then it is called to be relative airflow.
a. Direction: air parallel to and in opposite direction to the flight path of the a/c .
b. Condition: air close to but unaffected by presence of a/c, its temperature , velocity, and pressure not affected by the passage of a/c.
c. Magnitude: the magnitude of the Relative Air Flow is the TAS.
12. Effective Air Flow: if air does not possess all three of these qualities mentioned above it is referred as Effective Airflow.
13. Total Reaction: The resultant of all aerodynamic forces acting on the aerofoil section.
14. Centre of Pressure: The point on the chord line , through which lift is considered to be acting.
15. Lift: The aerodynamic force which acts at 90* to the Relative Air Flow.
16. Drag: The aerodynamic force which acts parallel to and in same direction of as of Relative Air Flow but in opposite direction of flight path.
17. Angle of attack/Aerodynamic Incidence: The angle between the chord line and Relative Airflow.
18. Effective angle of Attack: The angle between the chord line and the effective airflow is referred as the Effective Angle of Attack.
