Velocity profiles are measured at the upstream end $($surface $1)$ and at the downstream end $($surface$2)$ of the control volume shown in Figure $1.$ Surfaces $3$ and $4$ are streamlines and the flow is incompressible, two dimensional, and steady.

Consider the problem as a two$-$dimensional problem with unit width. Choose the control volume as the fluid insider the dashed lines, determine the drag force on the airfoil and calculate the drag coefficient. The vertical dimension $H_D=0\mathrm{.}025c.$ The pressure is constant over the entire surface of the control volume. You will need to calculate the vertical dimension of the upstream station $(H_{}).$