NESC0395 FLAC

FLAC FLAC-SI, Steady-State Flow and Pressure Distribution, 1-D Incompressible Flow Equation

NAME OR DESIGNATION OF PROGRAM, COMPUTER, DESCRIPTION OF PROBLEM OR FUNCTION, METHOD OF SOLUTION, RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM, TYPICAL RUNNING TIME, UNUSUAL FEATURES OF THE PROGRAM, RELATED AND AUXILIARY PROGRAMS, STATUS, REFERENCE, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHORS, MATERIAL, CATEGORIES

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1. NAME OR DESIGNATION OF PROGRAM: FLAC

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2. COMPUTERS

To submit a request, click below on the link of the version you wish to order. Only liaison officers are authorised to submit online requests. Rules for requesters are available here.

Program name	Package id	Status	Status date
FLAC	NESC0395/01	Tested	01-OCT-1973

Machines used:

Package ID	Orig. computer	Test computer
NESC0395/01	IBM 370 series	IBM 370 series

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3. DESCRIPTION OF PROBLEM OR FUNCTION

The flow analysis code FLAC calculates the steady-state flow and pressure distribution in an arbitrary network. The program includes the possibility of heat addition and mass addition in any portion of the network.

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4. METHOD OF SOLUTION

The equations that are solved are the one- dimensional momentum equation for incompressible flow in a duct and the conservation equations for flow and energy at each node. Density changes due to heat addition are included according to the perfect gas law. The method for solving the set of algebraic equations is a variation of the point relaxation technique.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The FLAC program does not consider two-phase flow or open-channel flow, as in hydraulics.

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6. TYPICAL RUNNING TIME

Approximately 30 seconds are required for a problem consisting of 100 branches. NESC executed the sample problem in 20 seconds on an IBM370/195.

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7. UNUSUAL FEATURES OF THE PROGRAM:

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8. RELATED AND AUXILIARY PROGRAMS:

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9. STATUS

Package ID	Status date	Status
NESC0395/01	01-OCT-1973	Tested at NEADB

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10. REFERENCE:

NESC0395/01, included references:

- G.J.  Malek:
  Development of the Flow Analysis Code FLAC
  GA-9482 (June 1969).

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11. MACHINE REQUIREMENTS

The computer storage requirements for FLAC are flexible, and the size of the various arrays can be adjusted to suit any problem. With all arrays set to their maximum, a problem consisting of 1500 branches and 700 nodes requires approximately 50,000 storage locations on the UNIVAC1108. 180K bytes of memory are needed for the IBM370 version.

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12. PROGRAMMING LANGUAGE(S) USED

Package ID	Computer language
NESC0395/01	FORTRAN-IV

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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED: EXEC2
(UNIVAC1108), OS/370 (IBM370).

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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

For
large problems, auxiliary data tapes can be used to store input information and results from the last iteration. These data tapes can be used to restart the problem in case of nonconvergence. The General Atomic system routine WARN permits the user to prescribe at run time a time interval parameter which is used as a warning period prior to job termination on the elapsed time job limit. Use of the statement CALL WARN (IWARN) returns a negative value of IWARN until the job enters the specified warning time interval after which a positive value is assigned. This routine is used to initiate writing to tape of restart data for subsequent runs. In the IBM version, subroutine WARN counts the number of iterations taken. If convergence is not achieved in IMAX iterations, the job terminates. The value assigned IMAX currently is 1000.

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15. NAME AND ESTABLISHMENT OF AUTHORS

   1108          G. J. Malek
                 General Atomic Company
                 P. O. Box 81608
                 San Diego, California  92138
   370           R. G. Olson
                 Detroit Edison
                 2000 Second Avenue
                 Detroit, Michigan  48226

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16. MATERIAL AVAILABLE

NESC0395/01

File name	File description	Records
NESC0395_01.001	SOURCE PROGRAM (FORTRAN)	746
NESC0395_01.002	JCL+SAMPLE PROBLEM	94
NESC0395_01.003	OUTPUT LIST OF SAMPLE PROBLEM	800

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17. CATEGORIES

H. Heat Transfer and Fluid Flow

Keywords: HTGR reactors, fluid flow, gases, heat transfer, pressure, temperature distribution.