CONTRACT (SANITIZED)

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78-03642A001300040003-0
• Release Decision: RIPPUB
• Original Classification: K
• Document Page Count: 2
• Document Creation Date: December 22, 2016
• Document Release Date: June 14, 2012
• Sequence Number: 3
• Publication Date: March 26, 1957
• Content Type: LETTER

I
Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642AO01300040003-0
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26 March 1957
11
This is the fourth of a series of informal letter reports concerning the
progress under Contract Nonr .1589(07) For the per'-)d 2i Febriary to 21
March 1957.
The mathematical treatment dealing with pressurized bodies has been ex-
tended so that maximum loads can be determined for any general body :;f
uniform cross section. These maxim.im loads are described in terms of the
cross sectional area, thickness of the body in the direction of the applied
load, pressure and length. This general result is quite useful since it
permits the determination of body configurations having some optimized
feature. The analysis of the mechanical properties of these bodies has
been conducted on the basis of purely isotherm a. conditio_ons. We are also
currently determining the b -)dies' bending ci racterist.cs on the basis of
adiabatic processes.
The extension of this study to bodies of non-uniform cross section is, of
course, our ultimate objective. Streamlined bodies, although basically
cylindrical in nature, will be best treated in the forthcoming work. We
have at this time some crude descriptions of strength of conic sections but
this must be extended greatly.
A rather extensive experimental program is taking form to verify the studies
which have been made in this area.
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Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642AO01300040003-0
SUBJECT: Contract
 Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642A001300040003-0
0 is
26 March 1957
Washington 25, D. C. Page two
A general equation has been developed to describe various forms of solid
bodies of revolution. This equation generates nine types of bodies, depend-
ing on the specification of the boundary conditions. An infinite assortment
of shapes is available within each of the nine types. This equation has
been compared to several existing lighter-than-air vehiclas and has been
found to be capable of describing most of them fairly well. The purpose
of this general equation is to allow the calculation of many of the physical
characteristics of the body, such as the volume, area, center of mass, e'c.
Another, and more important, use of this equation may be the determination
of fluid flow around such bodies. These calculations appear to be giite
difficult, and therefore we are investigating the use of various analogues,
one of which is the potential distribution around models in an electrolytic
trough.
The use of solar batteries has been long questioned as a means of deriving
energy on lighter-than-air systems. The relative advantage of solar bat-
teries over common types of batteries is basically dependent on the time.
interval over which they can be used. We have potted a number of these
rather interesting relationships for ordinary batteries and plan to enlarge
this to include many other energy soorc"s.
Our materials survey will be enlarged tj include the st.dy of degradation
of various plastic films, etc., when subjected to ordinary outdoor conditions.
The moment of instability for a streamlined object moving through a fluid
medium is derived from the theory of perfect fluids. It is found to be
proportional to the difference of the apparent mass between the longitudinal
and transverse directions, as well as to the dynamic pressure , volume and the
sine of twice the angle of attack. Mr. Froehlich is evaluating the ring
airfoil as a method of exerting correcting moinents.
A general equation relating the increased volume of varinis sizes of pres-
surized airships to envelope weight has been derived. It is found that
increased payloads can be carried on increasingly ,arver airships up to a
maximum value. It is also found that a r:,aximum size exists or a given type
airship construction, in that a larger airship would be incapable of carry-
ing the weight of the envelope alone.
Presumably, we shall be presenting an oral quarterly report in April. We
look forward to seeing you at that time.
Sincerely yours,
Geophysics Section
Declassified in Part - Sanitized Copy Approved for Release 2012/06/14: CIA-RDP78-03642A001300040003-0