The fundamental equation for the thin airfoil theory does not encompass which of the following approximations?

Vortex sheet is placed at the chord line

The angle of attack and slope of the camber line is small

Kutta condition is satisfied at the trailing edge

Camber line induced velocity distribution is the same for chord line

Correct Answer : Kutta condition is satisfied at the trailing edge

Explanation : Kutta condition is always satisfied at the trailing edge. This is the boundary condition for the camber line to be a streamline also and is not an approximation. While the other three statements are valid approximations, which have been made under the assumption of a thin airfoil where camber and chord line is very close.

Recently Updated in Aerodynamics Questions

Is laminar flow is used to increase the drag and reduce the lift?

True

False

Can Not Say

None of the above

Correct Answer : Option (A) : True

Explanation : The effect can also be exploited by devices such as aerodynamic spoilers on aircraft, which deliberately spoil the laminar flow to increase the drag and reduce the lift on the aircraft, which also used as a break to stop the aircraft

Example of turbulent flow?

Laminar flow

Flow on a symmetric airfoil

Smoking rises from cigarette

Turbulent flow on the airfoil

Correct Answer : Option (C) : Smoking rises from cigarette

Explanation : Smoke rising from a cigarette is mostly turbulent flow. However, for the first few centimeters, the flow is laminar. The smoke plume becomes turbulent as its Reynolds number increases, due to its flow velocity and the characteristic length.

Is lift is generated due to large pressure gradients on the upper side of the airfoil?

True

False

Can Not Say

None of the above

Correct Answer : Option (A) : True

Explanation : At higher angles, very large adverse pressure gradients that develop on the upper side as the airfoil attempts to generate more lift causes the boundary layer to separate, leading to a major disruption of the flow over the airfoil and the wing stalls.