Question

What is the flow over right circular cone at zero angle of attack is considered to be?

(a) One – dimensional

(b) Quasi three – dimensional

(c) Three – dimensional

(d) Quasi two – dimensional

This question was posed to me in exam.

The above asked question is from Quantitative Formulation in division Linearized and Conical Flows of Aerodynamics

Answer 1

Correct answer is (d) Quasi two – dimensional

Explanation: Since the cone is revolved around the z – axis, thus the conical flow is known to be axisymmetric. The spherical coordinate system used to determine the position in this flow is (r, ϕ, θ). But since the flow is axisymmetric, \( \frac {∂}{∂ϕ}\) = 0 and thus only (r, θ) coordinate system is used to determine the position in the flow making it quasi two0dimensional flow.