1. Aerodynamics

Inviscid Flow — Quiz

Test your understanding of inviscid flow with 5 practice questions.

Practice Questions

Question 1

In a Rankine half-body formed by superposing a uniform stream of speed $U_\infty$ and a point source of strength $Q$ at the origin, the stagnation point on the negative $x$-axis is located at $x =$

Question 2

In a two-dimensional, incompressible, inviscid flow around a circular cylinder with uniform free-stream velocity $U_\infty$ and superimposed circulation $\Gamma$, the lift force per unit span $L'$ according to the Kutta–Joukowski theorem is given by:

Question 3

For a cylinder of diameter $D=2a$ in a potential flow with free-stream velocity $U_\infty$ and circulation $\Gamma$, the lift coefficient $C_L$ per unit span is defined as $C_L = \frac{L'}{\tfrac12\rho U_\infty^2 D}$. Which expression for $C_L$ is correct?

Question 4

In a free vortex flow of circulation $\Gamma$ at the origin, the velocity potential $\phi(r,\theta)$ in polar coordinates is:

Question 5

D’Alembert’s paradox states that an inviscid, incompressible, potential flow predicts zero drag on a solid body. Which physical mechanism, neglected in potential flow theory, resolves this paradox by accounting for real fluid drag?