Consider a steady two-dimensional zero pressure gradient laminar flow of air over a flat plate as shown below. Find the ratio of displacement thickness to momentum thickness of the boundary layer at a distance of 2m from the leading edge.
Consider a steady two-dimensional zero pressure gradient laminar flow of air over a flat plate as shown below. The free stream conditions are u_{\infty}=100\;m/s,\rho_{\infty}=1.2\;kg/m^{3},p_{\infty}=1\;atm and \mu_{\infty}=1.8\times 10^{-5}\;kg/m-s. Find the ratio of displacement thickness to momentum thickness of the boundary layer at a distance of 2\;m from the leading edge.
Blasius solution for 2D zero pressure gradient laminar flow of air over a flat plate is \frac{\delta ^{*}}{x}=\frac{1.721}{Re_{x}^{1/2}} \\\frac{\theta}{x}=\frac{0.664}{Re_{x}^{1/2}} \\\Rightarrow \frac{\delta ^{*} }{\theta}=\frac{1.721}{0.664} \\=2.59
