NESC0577 FFEARS

FFEARS, Laplace Equation Boundary Value Problems with Dielectrics, X-Y-Z and Axisymmetric Geometry

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, REFERENCES, MACHINE REQUIREMENTS, LANGUAGE, OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED, OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS, NAME AND ESTABLISHMENT OF AUTHOR, MATERIAL, CATEGORIES

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1. NAME OR DESIGNATION OF PROGRAM: FFEARS

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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
FFEARS	NESC0577/01	Tested	01-MAY-1977
FFEARS	NESC0577/02	Tested	21-JUL-1983

Machines used:

Package ID	Orig. computer	Test computer
NESC0577/01	IBM 370 series	IBM 370 series
NESC0577/02	CDC CYBER 174	CDC CYBER 174

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3. DESCRIPTION OF PROBLEM OR FUNCTION

FFEARS is generally applicable for the solution of boundary value problems involving the Laplace equation using difference equations in axisymmetric or rectangular coordinates. It will handle virtually any configuration of dielectrics and floating electrodes, producing both equipotential and equifield plots, if desired.

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4. METHOD OF SOLUTION

Basic relaxation techniques are used. The difference equations employed are derived from Laplace's equation for isotropic dielectrics. These are solved iteratively at all points within the electrode configuration except on the interfaces between materials of different dielectric constant. Dielectric interfaces are solved by a technique developed by C. N. Dorny (Letters, Proc. IEEE, Vol. 57, pp. 856-858). Floating electrodes are treated as special dielectrics.

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5. RESTRICTIONS ON THE COMPLEXITY OF THE PROBLEM

The program treats any rectangular or axisymmetric configuration of dielectrics and small floating electrodes that can be described by a matrix of up to 201 x 201 points. All electrode and dielectric surfaces must lie on matrix points.

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6. TYPICAL RUNNING TIME

Solutions with errors of less than five percent are obtained in less than ten minutes.

NESC0577/02

NEA-DB executed the test case on CDC CYBER 174 in 652 CPU seconds.

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7. UNUSUAL FEATURES OF THE PROGRAM

A blowup routine permits the expansion and recomputation of sections of the plot to permit greater resolution.

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8. RELATED AND AUXILIARY PROGRAMS

This package is a modification of ALO-00262, transferred from the ALO-COSMIC collection.

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9. STATUS

Package ID	Status date	Status
NESC0577/01	01-MAY-1977	Tested at NEADB
NESC0577/02	21-JUL-1983	Tested at NEADB

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10. REFERENCES:

NESC0577/01, included references:

- J.E. Boers:
  FFEARS, A Digital Computer Program for the Simulation of Laplace
  Equation Including Dielectric Interfaces and Small Ungrounded
  Electrodes
  SC-RR-71 0377 (July 1971).
- FFEARS, ACC No. 577.360
  Argonne Code Center Programming Note 77-6 (November 22, 1976).

NESC0577/02, included references:

- J.E. Boers:
  FFEARS, A Digital Computer Program for the Simulation of Laplace
  Equation Including Dielectric Interfaces and Small Ungrounded
  Electrodes
  SC-RR-71 0377 (July 1971).
- Environmental Subroutines Required by FFEARS, ACC No. 577.6600B
  Argonne Code Center Programming Note 74-21, Rev. (November 18,
  1976).

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11. MACHINE REQUIREMENTS

The CDC6600 version requires 122,000 (octal) words of memory, 12 files on disk storage, and a SC-4020 plotter. The IBM360 version requires 350K bytes to compile, 288K bytes to execute, 11 files on disk storage, and a CalComp plotter.

NESC0577/02

Execution of the test case on CDC CYBER 174 requires 160,000 octal words of main storage.

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12. PROGRAMMING LANGUAGE(S) USED

Package ID	Computer language
NESC0577/01	FORTRAN-IV
NESC0577/02	FORTRAN-IV

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13. OPERATING SYSTEM UNDER WHICH PROGRAM IS EXECUTED

SCOPE 3.3 (CDC6600), SCOPE 2.1 (CDC7600), OS/360 (IBM360), OS/370 (IBM370). NOS 1.4-531 (CDC CYBER 174).

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14. OTHER PROGRAMMING OR OPERATING INFORMATION OR RESTRICTIONS

Several subroutines and functions necessary to the operation of the plotting portion of the program are not included in the source deck. For the CDC6600 version, they are a part of the standard SCORS plotter package for the SC-4020 plotter, and must be furnished by the user or replaced by equivalent locally-available subroutines. The IBM360 version uses standard CalComp plotting calls.

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15. NAME AND ESTABLISHMENT OF AUTHOR

   6600          J. E. Boers
                 Division 2354
                 Sandia Laboratories
                 P. O. Box 5800
                 Albuquerque, New Mexico  87115
   360           H. E. Edwards
                 National Energy Software Center
                 Argonne National Laboratory
                 9700 South Cass Avenue
                 Argonne, Illinois  60439

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16. MATERIAL AVAILABLE

NESC0577/01

File name	File description	Records
NESC0577_01.001	FFEARS SOURCE - FORTRAN IV EBCDIC	1690
NESC0577_01.002	FFEARS SAMPLE PROBLEM INPUT	259
NESC0577_01.003	FFEARS SAMPLE PROBLEM OUTPUT	4660
NESC0577_01.004	JOB CONTROL CARDS AND INFORMATION	45

NESC0577/02

File name	File description	Records
NESC0577_02.003	FFEARS INFORMATION FILE	18
NESC0577_02.004	FFEARS JCL	8
NESC0577_02.005	FFEARS SOURCE (FORTRAN-4)	1434
NESC0577_02.006	DUMMY SUBROUTINE	81
NESC0577_02.007	FFEARS INPUT FOR TEST CASE	258
NESC0577_02.008	FFEARS OUTPUT OF TEST CASE	4646

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17. CATEGORIES

P. General Mathematical and Computing System Routines

Keywords: Laplace equation, dielectric materials, electrodes.