RSICC CODE PACKAGE PSR 569

1.         NAME AND TITLE

ORTHIS: Steady-State Heat Conduction in 2-D X-Y, R-Z and R-Theta Geometry;

ORTHAT: Transient Heat Conduction in 2-D X-Y, R-Z and R-Theta Geometry.

2.         CONTRIBUTORS

Oak Ridge National Laboratory, Oak Ridge, TN, USA through the NEADB, Issy-les-Moulineaux, France.

3.         CODING LANGUAGE AND COMPUTER

Fortran IV (P00569I036000).

4.         NATURE OF PROBLEM SOLVED

ORTHIS and ORTHAT are designed to solve steady-state and transient heat conduction problems, respectively, in two-dimensional geometries. Either Cartesian (x-y) or cylindrical (r-z, r-theta) coordinate systems may be used. Thermal properties, heat generation rates, and boundary conditions may be functions of position, time, or temperature.

5.         METHOD OF SOLUTION

ORTHIS uses the iterative method of successive overrelaxation to solve the steady-state problem.  In addition to overrelaxation it also uses a dominant-error-mode extrapolation procedure to increase the rate of convergence. ORTHAT uses a modified alternating-direction implicit method to solve the transient problem.  The input for both programs has been designed in an easily usable free-form style.

6.         RESTRICTIONS OR LIMITATIONS

Maxima of –

1000 vertical nodes

1000 horizontal nodes

10000 total nodes (rows*columns)

50 vertical regions

50 horizontal regions

2500 total regions (rows*columns)

300 materials

1500 steady-state iterations

5000 transient time-steps

7.         TYPICAL RUNNING TIME

Both programs execute in 2 to 3 minutes.

8.         COMPUTER HARDWARE REQUIREMENTS

ORTHIS requires 700K, ORTHAT requires 1024K bytes.

9.         COMPUTER SOFTWARE REQUIREMENTS

A Fortran compiler is required.  Source code is written in Fortran IV and modest changes may be required for code compilation on modern platforms.

10.       REFERENCES

a.   included in documentation

R.C. Durfee and C.W. Nestor, Jr., “ORTHIS, ORTHAT - Two Computer Programs for Solving Two-dimensional Steady-state and Transient Heat Conduction Problems,” ORNL-TM-3324 (July 1971) – includes ACC Programming Note 73-3 (July 31, 1972).

11.       CONTENTS OF CODE PACKAGE

The package is transmitted in a self-extracting executable which contains source, sample problems and documentation.

12.       DATE OF ABSTRACT

June 2012.

KEYWORDS:     FUEL ELEMENTS, HEAT TRANSFER, R-THETA, STEADY-STATE CONDITIONS, TEMPERATURE DEPENDENCE, THERMAL CONDUCTIVITY, TIME DEPENDENCE, TWO-DIMENSTIONAL, X-Y