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