Computer program determines temperature profiles and heat transfer rates for shadow shielded cryogenic tank. Tank, shields, and thermal radiation heat source are all axisymmetric. Thermal analysis considers varying shield and tank temperatures, surface properties, and geometric arrangements. Similar heat source properties are also considered

Boyle, R. J.

Knoll, R. H.

English

NASA Technical Reports Server

May 1971	 Brief 71-10115 
NASA TECH BRIEF 
Lewis Research Center	
_4V 
NASA Tech Briefs announce new technology derived from the U.S. space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the. Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Computer Program for Thermal Analysis of Shadow Shields in a Vacuum 
The problem: 
To perform a thermal analysis of shadow shielded 
cryogenic storage tanks. Shadow shields are used to 
reduce radiation heat transfer rates in a vacuum 
environment, a necessity in the storage of cryo-
genics in space for long periods of time. The thermal 
analysis of a shadow shielded system must con-
sider varying temperatures and surface properties of 
the shields and tank, as well as their geometric 
arrangement. Similar properties of the heat source 
must also be taken into consideration. 
The solution: 
A computer program which determines temperature 
profiles and heat transfer rates for a shadow shielded 
cryogenic tank. The tank, shields, and thermal ra-
diation heat source are all axisymmetric. 
How it's done: 
The program was developed using Gebhardt's grey 
body radiation interchange method for diffuse sur-
faces. The non-uniform radiosity results are obtained 
through the use of successively smaller areas in 
a finite element analysis. 
The surfaces of the heat source and the tank are 
arranged so that no surface views more than one 
other surface. When more than one element is used
to represent the surface of a shield, temperature pro-
files may be calculated across the shield. It is also 
possible to assume that the shield has a uniform 
temperature even though the radiosity varies across 
the two surfaces. The system of shields is divided 
into enclosures and the temperatures are found in 
an iterative fashion. Variations in surface emis-
sivity and shield conductivity with variations in tem-
perature can be accomplished. For an increase in 
running time, results can also be obtained for a 
finite conductivity shield. 
Notes: 
1. This program is written in FORTRAN IV for use 
on the IBM-7094 computer. 
2. Inquiries may be directed to: 
COSMIC 
Barrow Hall 
University of Georgia 
Athens, Georgia 30601 
Reference: B71-10115 
Patent status: 
No patent action is contemplated by NASA. 
Source: R. J. Boyle and R. H. Knoll 
Lewis Research Center
(LEW-11236) 
Category 09 
MW
This document was prepared under the sponsorship of the National 
Aeronautics and Space Administration. Neither the United States 
Government nor any person acting on behalf of the United States
Government assumes any liability resulting from the use of the 
information contained in this document, or warrants that such use 
will be free from privately ownedrights.
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Computer program for thermal analysis of shadow shields in a vacuum

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