Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/382

§ 234 forces, assuming the reaction exactly at right angles to the surfaces of the plane—that is to say, neglecting skin-friction. The curve drawn is a so-called corrected curve, the basis of the correction being given in the Memoir, and which we will now proceed to examine.

Let us first draw two curves, from theoretical considerations alone, on the basis (a) that the fluid is frictionless, and (b) that there is a tangential force due to a coefficient of skin friction $$\xi =$$ .025 effective on one face only of the plane—that is, an