NESC9911 CNVUFAC GRAY.

1. NAME OR DESIGNATION OF PROGRAM:  CNVUFAC GRAY

3. DESCRIPTION OF PROGRAM OR FUNCTION

CNVUFAC, the General Dynamics heat-transfer radiation view program, was adapted for use on the LLNL computer system. The input and output were modified, and a node incrementing logic added for compatibility with TRUMP (NESC 771) thermal analyzer and related codes. The program performs the multiple integration necessary to evaluate the geometric black-body  radiation node to node view factors. CNVUFAC uses an elemental area  summation scheme to evaluate the multiple integrals. The program permits shadowing and self-shadowing. The basic configuration shapes that can be considered are cylinders, cones, spheres, ellipsoids, flat plates, disks, toroids, and polynomials of revolution. Portions of these shapes can also be considered. Card-image output containing node number and view factor information is generated for input to GRAY, a related code.
GRAY performs the matrix manipulations necessary to convert black-body radiation heat-transfer view factors to gray-body view factors as required by thermal analyzer codes. The black-body view factors contain only geometric relationships. GRAY allows the effects of multiple gray-body reflections to be included. The resulting effective gray-body view factors can then be used with the corresponding fourth-power temperature differences to obtain the net radiative heat flux. GRAY accepts a matrix input or the card-image output generated by CNVUFAC. The resulting card-image GRAY output is in a form usable by TRUMP.

4. METHOD OF SOLUTION:

5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM:

6. TYPICAL RUNNING TIME:

The test case included in this package was executed at  NEADB on a CRAY-XMP computer in 23 seconds of CPU time.

The test case included in this package was executed at  NEADB on a CRAY-XMP computer in 4.5 seconds of CPU time.

7. UNUSUAL FEATURES OF THE PROGRAM:

8. RELATED AND AUXILIARY PROGRAMS

TRUMP a steady state and transient, 1, 2 and 3-D potential flow and temperature distribution code.

10. REFERENCES:

- Robert L. Wong:
  User's Manual for CNVUFAC, the General Dynamics Heat-Transfer
  Radiation View Factor Program
  UCID-17275 (June 25, 1976).
- R.L. Wong
  GRAY: A Program to Calculate Gray-Body Radiation Heat-Transfer
  View Factors from Black-body View Factors
  UCID-17277 (June 14, 1976).

11. MACHINE REQUIREMENTS:

Test case execution required 1,003,000 (dec) words of CRAY-XMP main storage.

Test case execution required 842,752 (dec) words of CRAY-XMP main storage.

13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED:

The program ran on CRAY-XMP under UNICOS 5.1.10 with the CFT77 4.1 FORTRAN 77 compiler.

The program ran on CRAY-XMP under UNICOS 5.1.10 with the CFT77 4.1 FORTRAN 77 compiler.

14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS:

15. NAME AND ESTABLISHMENT OF AUTHORS

          R.L. Wong
          Lawrence Livermore National Laboratory

File name	File description	Records
NESC9911_01.001	Information file	41
NESC9911_01.002	JCL and control information	20
NESC9911_01.003	CNVUFAC source program	949
NESC9911_01.004	CNVUFAC sample problems input	32
NESC9911_01.005	CNVUFAC sample problems output	256

File name	File description	Records
NESC9911_02.001	Information file	41
NESC9911_02.002	JCL and control information	20
NESC9911_02.003	GRAY source program	432
NESC9911_02.004	GRAY sample problems input	56
NESC9911_02.005	GRAY sample problems outut	498