602 BELL SYSTEM TECHNICAL JOURNAL 



The angle (5) between the resultant and normal wind forces was 

 determined through the use of equation (4). The variations in this 

 angle with the obliquity of the wind or the angle a are given for both 

 sizes of wire in Figs. 9 (0.104-inch wire) and 10 (0.165-inch wire). From 

 these graphs the following relations appear to exist in this range : 



(a) For a given angle a the magnitude of the angle 5 is inversely 

 proportional to the product of velocity and wire diameter {VD), 



S = 

 This relation can be written 



5 = 



{vh).._ 



a=constant 



where VD/v is the familiar Reynolds number. 



(6) For each size of wire and a given actual wind velocity the angle 8 

 increases with the angle a. Hence, 5 = f(a, V, D)v, D=constant- Since 

 the Reynolds number can also be considered constant 



5 = ip{a, VD/v)v, D, i'=constant- 



Conclusion 



These tests indicate that the normal force on a wire due to an oblique 

 wind is proportional to the square of the resolved component of the 

 actual wind velocity for angles up to 60° from the normal to the wire. 

 The expression for the normal force per unit length of wire is 

 Fn = K{V cos aYD, where V is the actual wind velocity and D is the 

 wire diameter. The tangential component is relatively small as 

 compared to the normal component. 



