Question

Which of the following statement(s) is/are true with regards to Kutta condition for flow past airfoils?

• A. It is utilized to determine the circulation on an airfoil.
• B. It is applicable only to airfoils with sharp trailing edge.
• C. The trailing edge of an airfoil is a stagnation point.
• D. The flow leaves the trailing edge smoothly.

Hint:

The Kutta condition ensures smooth flow at the trailing edge and establishes the correct circulation on an airfoil for lift generation.

Answer 1

The Correct Option is A, B, D

Step 1: Purpose of Kutta condition.
The Kutta condition enforces that the flow leaves the sharp trailing edge smoothly. This determines the correct circulation needed for lift. Therefore, (A) and (D) are correct.

Step 2: Applicability.
The Kutta condition applies to airfoils with a sharp trailing edge. This is required so the flow can choose a physically realistic stagnation location at the trailing edge. Thus, (B) is also correct.

Step 3: Why (C) is incorrect.
The trailing edge is not generally a stagnation point in real flow; instead, flow leaves it smoothly at finite velocity.

Final Answer: A, B, D