Page:Aerial Flight - Volume 1 - Aerodynamics - Frederick Lanchester - 1906.djvu/231

Rh is calculated and plotted. The ordinate scale is given in terms of maximum value = 1, and in terms of $$C,$$ value in which case becomes .440.

According to the theory advanced by the author (Chap. IV.), the case now under discussion is indeterminate; the reaction on the plane is a function of the strength of the cyclic motion and its velocity of translation, and is not dependent upon the angle in the particular case of the plane of infinite lateral extent. If the plane, although of great aspect ratio, be of finite length, then a dispersal of the energy of the cyclic motion will take place, and in order that a steady state should exist this energy must be continuously renewed by the work done in proportion, which requires some specific angle in order that a stated load shall be sustained.

In a real fluid it is evident that the type of motion depicted in Figs. 71 and 75 could not exist in toto; the abruptness of the motion round the sharp edges of the plane would give rise to discontinuity. From our knowledge of problems of this kind we Rh