roswell

a.·~
(H) dt • K dt
where K is a constant.
We may state the relationship (13) in terms of rate of trans-
fer and area of the opening, assuming dft to be constant across
the opening: dz
(15) 9r- -K1Dfz"A
where:
~: DI8.Ss transfer of lifting gas
~: variation of concentration of lifting gas
dz in direction •
A : area of opening
In order, then, to determine the rate of loss of lifting gas
by diffusion· through the open appendix 1're JllUSt:
(a) determine the relationship between the coefficient of
diffusio~ D,and altitude (or pressure and temperature)
(b) determine the loss of lift by diffusion through the appendix
at any convenient altitude (i.e. at the ground)
(c) derive a relationship between loss at the ground and loss
at any altitude.
However, determination of valid relationships to find diffu-
sion through the appendix opening would require large scale
laboratory testing and then tedious derivation of mathematical
equations, a study in research in itself. It was deemed more
practical to red~ce or eliminate this type of loss of ·lift
by reduction of the area of the opening by use of a relief
valve system as explained in Part II of this report, "Operations,"
PP• 8-14.
F. Bursting Pressure and Appendix Considerations
Bursting pressure of a balloon can be computed from the equation:
(1) ~p=~ for failure of the fabric or film,
where:
-47-