TABLES 143-145. 

 AERODYNAMICS. 



The following tables, based on Eiffel, show the variation of the resistance coefficient K, with 

 the angle of impact i, the aspect (ratio of leading edge to chord length), shape and velocity V 

 in the formula 



tf(kg/m 2 ) = KS(m 2 )fF(m/sec.)} 2 

 The value of K for km/hour would be 0.77 times greater. 



TABLE 143. Variation of Air Resistance with Aspect and Angle. 



Cylinder, base JL to wind: 

 Diameter of base, 30 cm 

 Diameter of base, 15 cm 

 Cylinder, base 

 Cylinder, base 



TABLE 144. Variation of Air Resistance with Shape and Size. 



Length, o cm iR* 2R* *R* 6R* SR* 



o cm 



K = .0675 .068 .055 .050 

 K= .066 .066 .055 .051 .051 .0515 

 to wind: diameter base, 15 cm, length, 60 cm K = .040 

 to wind: diameter base, 3 cm, length, 100 cm K = .060 



.059 



Cone, angle 60, diam. base, 40 cm, point to wind, solid K = .032 



Cone, angle 30, diam. base, 40 cm, point to wind, solid K = .021 



Sphere, 25 cm diam. K = .on 



Hemisphere, same diam., convex to wind K = .021 



Hemisphere, same diam., concave to wind K = .083 



Sphero-conic body, diam., 20 cm, cone 20, point forward K = .010 



Sphero-conic body, diam., 20 cm, cone 20, point to rear K = .0055 



Cylinder, 120 cm long, spherical ends to wind K = .012 



The wind velocity for the values of this table was 10 m/sec. 



Tables 143 and 144 were taken from "The Resistance of the Air and Aviation," Eiffel, trans- 

 lated by Hunsaker, 1913. 



* In the case of these cylinders the percentages due to skin friction are 2, 3, 6, 8, n and 16 

 per cent respectively, excluding the disk. 



TABLE 145. Variation of Air Resistance with Shape, Size and Speed. 



This table shows the peculiar drop in air resistance for speeds greater than 4 to 12 meters per 

 second. Another change occurs when the velocity approaches that of sound. 



Taken from "Nouvelles Recherches sur la resistance de 1'air et 1'aviation," Eiffel, 1914. 

 SMITHSONIAN TABLES. 



