roswell

balloon at any point ~ may be expressed as:
(4) =2( Dlu- t.e•]v.
Therefore.,. maximum allowable balloon pressure at any plane i-1
will be:
(5)
Equation (5) me.y be plotted in terms of bursting ·pressure and lle
for any given diameter balloon. A straight line through the
origin and tangent to the plot of Equation (5) will indicate
the maximum allowable(dptde)Git (1-8) for any given diameter bal-
loath Comparl.ng the me.ximmn allowable (dp/de)0 1( with a chart
of altitude vs. pressure in the atmosphere will indicate the
minimum altitude at which the balloon can be allowed to be full.
From an altitude-buoyancy table for any given diameter balloon,
the maximum allowable buoyancy. or maximum allO?rable gas in-
flation ean be obtained.
Figure 26 is a plot of equations (3) and (5) for .001 11 poly-
ethylene (sf= 900 psi ) balloons of 20'' 30' and 70'
diameters. 2
Fig. 25.
Relationship a)bz, for balloon.
-49-
:.:I
•<4 1·01--f-tt----t-
Fig. 26.
• .25&• lo-• Pliltt.
A,- pel
Graph of equations (3) and (5).