Aerodynamics Multiple Choice Questions & Answers (MCQs) on “Airfoil Nomenclature”.
1. Who designed the nomenclature of airfoil?
a) NACA series
b) EULAR series
c) EPPLER series
d) CLARK series
Answer: a
Clarification: The nomenclature of airfoil is designed by the NACA series. The shape of the NACA airfoil is described using a series of digits following the word NACA. The NACA identified different airfoils shape with a logical numbering system, such as symmetric airfoil and cambered airfoil.
2. Purpose of camber in an airfoil is ____________
a) to increase maximum drag
b) to increase maximum lift
c) to decrease maximum lift
d) to decrease maximum drag
Answer: b
Clarification: The main purpose of camber is to increase the maximum lift in an airfoil. The maximum lift coefficient can get by increasing the camber in an airfoil. Some recent design use negative camber. That airfoil is called the supercritical airfoil. This type of airfoil is used in the supersonic flight and to produce a higher lift to drag ratio.
3. Is shape of the airfoil depends on thickness?
a) True
b) False
Answer: a
Clarification: The shape of the airfoil depends on the thickness of the airfoil. The thickness of an airfoil varies along the chord. The thickness is measured perpendicular to the chord line. In NACA series the last two digits indicate the percentage of thickness.
4. What is a chord?
a) Distance between leading edge and chord
b) Distance between chord and chamber
c) Distance between leading edge and trailing edge
d) Distance between trailing edge and chord
Answer: c
Clarification: Distance between leading edge and the trailing edge is called chord. Chord refers to the imaginary straight line joining the leading edge and trailing edge of an airfoil. The chord length is the distance between the trailing edge and the point on the leading edge, where the chord intersects the leading edge.
5. Purpose of leading edge is to ______________
a) allow the wing to operate at high angle of attack
b) allow the wing to operate at low angle of attack
c) allow the wing to operate at stall condition
d) allow the wing to operate in level condition
Answer: a
Clarification: Leading edge is a part of the airfoil. Leading edge allows the wing to operate at a high angle of attack. Slats are placed at the leading edge. These are aerodynamic surfaces on the leading edge of the wing. These are high lift devices used for short takeoff.
6. What is the purpose of trailing edge?
a) Airflow rejoins
b) Airflow separated
c) Vortex are created
d) Stalling will created
Answer: a
Clarification: Trailing edge is a part of airfoil. Trailing edge of an aerodynamic surface such as awing is its rear edge. Where the airflow will separate at the leading edge and rejoins at the trailing edge. Ailerons are placed at the trailing edge of the wing and rudder, elevator is placed at the trailing edge of tail.
7. What is the shape of the airfoil at the leading edge?
a) Semi-circular
b) Curve
c) Straight
d) Circular