TABLE 341A. 

 .0032 



345 



>KIN FRICTION ON FLAT PLATES (FIGS. 11, 12) (concluded) 



.000 8 



200 500 I000 2000 5000 10,000 20,000 50,000 100,000 



REYNOLDS NUMBER Rq 



Fig. 12. — The local skin-friction coefficient on a flat plate plotted against the Reynolds 

 number for a turbulent boundary layer. 



TABLE 342.— STANDARD ATMOSPHERE 135 



Standard atmospheric values are given up to altitudes of 65,000 feet, and quantities 

 that have been found to be of use in the interpretation of airspeed and related factors are 

 included (Table 343). These quantities are the pressure p in pounds per square foot, the 

 pressure p in inches of water, the speed of sound a, the coefficient of viscosity t\, and the 

 kinematic viscosity v. The values for the coefficient of viscosity y and the kinematic vis- 

 cosity v are not standard values since a standardization of air viscosity has not been agreed 

 upon as yet. The values listed for i\ and v are believed to be sufficiently accurate, however, 

 to be useful in calculations requiring viscosity of air. The coefficierit of viscosity rj was com- 

 puted from the formula 



v= 10 8 T + 216 ' 



The kinematic viscosity of air v was obtained from the definition v = — The quantity 



— . . p 



1/Vo- is given to facilitate the computation of the true airspeed V from the equivalent 



airspeed V '«. 



33.42 vT where T is the 

 1.4 was assumed to hold 



The speed of sound in miles per hour is computed from a 

 temperature in degrees Fahrenheit absolute. A value of y 

 throughout the temperature range. 



The values of the standard atmosphere are based upon the following values : 



Sea-level pressure p = 29.921 inHg 



= 407.1 inH 2 



= 21 16.2 lb/ft 2 

 Sea-level temperature to = 59° F 

 Sea-level absolute temperature To = 518.4°F abs 

 Sea-level density P o = 0.002378 slug/ft 3 

 Gravity g — 32.1740 ft/sec 2 



Temperature gradient -yr- = 0.0035661 7° F/ft 

 an 



The altitude of the lower limit of the isothermal atmosphere = 35,332 ft 



Specific weight of mercury at 32°F = 848.7149 lb/ft 8 



Specific weight of water at 59°F = 62.3724 lb/ft 8 



135 Aiken, William S.. Jr.. Standard nomenclature for airspeeds with tables and charts for use in 

 calculation of airspeed, NACA Rep. No. 837, 1947. Warfield, Calvin N., Tentative tables for the prop- 

 erties of the upper atmosphere, NACA TN No. 1200, January 1947. 



(continued) 



SMITHSONIAN PHYSICAL TABLES 



