Discuss the flow pattern around a circular obstacle associated with the
complex potential \[ \Omega (z)=u_0\left (z+\frac {a^2}{z}\right )+\frac {i\gamma }{2\pi }\log z. \]
Show that \(r=a\) is a streamline.
Determine the asymptotic velocity when \(z\to \infty \). Sketch the flow when \(\gamma =0\).
Use the Blasius formula \[ F_x-iF_y=\frac {1}{2}i\rho \int _C \left (\frac {d\Omega }{dz}\right )^2\,dz \] to determine the lift on the obstacle when \(\gamma \neq 0\).