86 WORLDWIDE EFFECTS OF ATOMIC WEAPONS _ &3 50 Upper limit of Stokes’ flow & 20 50 s a 10 “5 40 = oe u Ee ! - 5 - 2 > ot e s 9 . £05} f | = 7 Re Le REFERENCES | 100 Time (in doys) a 02 3 's 30 Ss 5 £ io 2 'o NS 100 Time (in yr } 5 i 2. 5 m2 5 i” 2 8 i 2 5 1 2 5 2 Time required for porticlas to fall to seo level (in sec) ~\ \ 5 Ig! °o oO o ~ Ratio of etiipsoid velocity to sphere velocity TN 1200, 1947. 0.7 Note: ° n Axis ais vertical 03 04 0608 | Shape porometer 2 (o//be ) 3.64 6 8 10 Fig. 10—Ratio of terminalvelocity of ellipsoid with axes a,b, ande¢ to terminal velocity of sphere of same volume 6. Perry, J. H. (ed.), Chemical Engineers Handbook, McGraw-Hill Book Company, Inc., 7. WarFieLp, C. N., Tentative Tables for the Properties of the Upper Atmosphere, NACA Ratio: bf/e zt Z02 1. McNown, J. S., aNpD J. Mavaika, "Effects of Particle Shape of Settling Velocities at Low Reynolds Numbers,” Trans. Am. Geophys. Union, Vol. 31, 1950, p. 74. 2. OBERBECK, A., Crefle, Vol. 81, 1876, p. 62; see also, H. Lamb, Hydrodynamics, Dover Publications, New York, 1945, p. 604, 3. CUNNINGHAM, E,, Proc. Roy. Soc., Vol. 83 (1), 1910, p. 357. 4. Epstein, P. S., “On the Resistance Experienced by Spheres in Their Motion through Gases,” Phys. Rev., Vol. 23, 1924, p. 710. 5. KNupsen, M., ano S. Weper, Ann. Physih, Vol. 36, 1911, p. 981. 1950, p. 1019. Fig. 9—-Time required for spherical particles of density p’ = 2 gm/em?® to fall from a given initial altitude to sea level as a function of diameter O50.! 87 ratio of the terminal velocity of fall for ellipsoids to the terminal velocity of a sphere of the same volume. The values given are accurate only in the Stokes’ range of flow but may be used as an approximation even when d/X 10. tnitiol altitude (km) = Y APPENDIX II 20