text: camber at 40 percent chord, 12 percent thick- 
  typical 
  ness at 30 percent chord)--a 
  “conventionaal” airfoil section. The lift curve 
  show a steady increase in cl with 
  increasing 
  RN. However, note that a>maller change in 
  cr occurs between Reynolds Numbers of 6.0 
  ad 9.0 million 
  than occurs between 0.1 and 
  3.0 million. 
  In other words, greater changes 
  in CI occur in the range of Reynolds Num- 
  bers zhere the laminar (low energy) boundary 
  layer predominates. The drag curves for the 
  section show essentially the same feature-the 
  greatest variations occur at very low Reynolds 
  Numbers. Typical full scale Reynolds Num- 
  bers for aircraft in flight may be 3 to 5@O million 
  where the boundary layer is predominately 
  involve 
  turbulent. Scale model 
  Reynolds Numbers of 0.1 to 5 million where 
  the boundary layer be predominately laminar. 
  Hence, the “scale” corrections are very neces- 
  sary to correlate the principal aerodynamic 
  characteristics. 
  The very 
  
  fairly 
  
  large changes in aerodynamic 
  characteristics at low Reynolds Numbers are 
  due in great part to the low energy laminar 
  boundary layer typical of low Reynolds Num- 
  bers. Low Reynolds Numbers are the result 
  of some combination of low velocity, small 