Chapter 5, Problem 5.18P

The drag on an airplane wing in flight is known to be a function of the density of air $\left(\rho \right)$, the viscosity of air $\left(\mu \right)$, the free-stream velocity $\left(U_{\infty }\right)$, a characteristic dimension of the wing ( s ), and the shear stress on the surface of the wing $\left({\tau }_s\right)$.

Show that the dimensionless drag, $\frac{{\tau }_s}{\rho U_{\infty }{}^2}$, can be expressed as a function of the Reynolds number, $\frac{\rho U_{\infty }s}{\mu }$.