1. NAME AND TITLE

AT123D: Analytical Transient One-, Two-, and Three-Dimensional Simulation of Waste Transport in an Aquifer System.

2. CONTRIBUTOR

Oak Ridge National Laboratory, Oak Ridge, Tennessee.

3. CODING LANGUAGE AND COMPUTER

Fortran IV; IBM 3033.

4. NATURE OF PROBLEM SOLVED.

AT123D is developed to compute the temporal-spatial distribution of contaminant concentration or temperature resulting from artificial input into aquifer systems. The assumptions include homogeneous flow field, constant aquifer properties, and simple aquifer geometry.

5. METHOD OF SOLUTION

The advective-dispersion equation augmented with sorption, decay, and source/sink is solved analytically by means of Green's function. This makes the solution applicable to one-, two-, and three-dimensional problems as desired. The solution is written in terms of convolution integrals of the source/sink and boundary conditions and Green's functions. AT123D is developed to implement these integrals.

6. RESTRICTIONS OR LIMITATIONS

Because it is an analytical solution, computer storage requirement is minimal. However, when the dispersivity is very small, the convergence in evaluating the series is very slow causing excessive computational time. Under such conditions, a warning message will appear in the output. The user should then invoke the option of infinite depth or infinite width depending on the nature of the problem.

7. TYPICAL RUNNING TIME

The sample problem computing the concentration distribution at 72 points for 100 time steps required 7.6 seconds of CPU time on the IBM 3033.

8. COMPUTER HARDWARE REQUIREMENTS

AT123D is operable on the IBM 3033 computer.

9. COMPUTER SOFTWARE REQUIREMENTS

The sample problem was executed on the IBM FORT H compiler.

10. REFERENCE

G. T. Yeh, "AT123D: Analytical Transient One-, Two-, and Three-Dimensional Simulation of Waste Transport in the Aquifer System," ORNL 5602 (March 1981).

11. CONTENTS OF CODE PACKAGE

Included are the referenced document and one (1.2MB) DOS diskette which contains the source code plus sample problem input and output.

12. DATE OF ABSTRACT

June 1982.