Milgram 



H 



or 



U/U, 



2.6 



2.5 



2.4 



2.3 



2.2 



2.1 



2.0 



i .9 



I .8 



1.7 



1.6 



I .5 



I .4 



I .3 



I .2 - 



1.0 



0.5 0.6 0.7 0.8 0.9 1.0 



Fraction of the Chord 



Fig. 4 - Calculations from four semi-empirical 

 boundary layer theories 



author. They are those of Von Doenhoff and Tetervin (1943), Truckenbrodt (1955), 

 Spence (1956), and Moses (1964). For ail of these semi-empirical theories, a 

 skin friction law must be used and a number of investigators have deemed the 

 Ludwieg- Tillman Law (1950) to be the most reliable of these laws. This law 



1416 



