Ruggles (1970 



Sheppard (1958) 



o 

 u 



Davidson and Portman (1971) 

 smooth flow! 



Smith (1967 



10 



12 



14 



16 



U|om/s-' 



18 



Figure 3. Various suggested forms of the drag coefficient (Cg) 

 versus windspeed (Ug) at 10 meters (from McConathy, 

 1972). 



