GMS:LMG Package
The LMG1 package is only supported in GMS versions prior to 8.0. The LMG1 Package information can be found here.
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This contains information about functionality available starting at GMS version 8.0. The content may not apply to other versions. |
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| MODFLOW | |
|---|---|
| Pre-processing | |
| MODFLOW Commands | |
| Building a MODFLOW Model | |
| Map to MODFLOW | |
| Calibration | |
| Packages Supported in GMS | |
| Saving a MODFLOW Simulation | |
| Importing MODFLOW Files | |
| Unsupported MODFLOW Features | |
| Run MODFLOW | |
| Post-processing | |
| MODFLOW Display Options | |
| MODFLOW Post-Processing Viewing Options | |
| Reading a MODFLOW Simulation | |
| Tutorials | |
| Packages | |
| Flow: | BCF6, HUF, LPF, UPW |
| Solvers: | SMS |
| Other: | UZF1 |
LMG3 package offers some improvements over the LMG1 package for certain types of problems. The LMG3 package is backward compatible with LMG1 input files. For non-linear problems and simulations which use several time steps, subsequent matrices to be solved for often change only slightly in their algebraic properties. In this case the LMG3 offers a possibility to accelerate the overall simulation time enormously.
Contents
- 1 MXITER. Maximum outer iterations
- 2 MXCYC. Maximum inner iterations
- 3 RCLOSE. Inner iteration closure criterion
- 4 HCLOSE. Outer iteration closure criterion
- 5 CONTROL. LMG version to use
- 6 Damping method
- 7 DAMP. Accleration Parameter
- 8 DUP. Max Acceleration
- 9 DLOW. Min Acceleration
- 10 Conjugate Gradient
- 11 Stor1, Stor2, Stor3
- 12 IOUTAMG. Output control
- 13 Reset
MXITER. Maximum outer iterations
This value is the maximum iterations, or calls to the solver. For linear problems, this value can be 2. For non linear problems, this values should be larger, but generally less than 50.
MXCYC. Maximum inner iterations
This value is the maximum number of iterations per call to the solver. The default value is 50, and this is sufficient for most problems.
RCLOSE. Inner iteration closure criterion
Same as RCLOSE for the GMG solver package. The PCG algorithm computes the l2norm of the residual and compares it against RCLOSE. In LMG1 this was called Budget Closure Criterion. When the scaled norm of the matrix equations is less than this value then the solver iteration stops.
HCLOSE. Outer iteration closure criterion
Head change convergence criterion for nonlinear problems. After each linear solve (inner iteration), the maximum norm of the head change is compared against HCLOSE.
CONTROL. LMG version to use
This variable allows the user to select either LMG1 or LMG2 version of the LMG solver.
Damping method
Three different damping methods are available: constant, Adaptive damping using the Cooley method, or Adaptive RRR damping using the relative reduced residual. Refer to the official package documentation for more explanation on the different damping methods.
DAMP. Accleration Parameter
This value is used if the acceleration method is set to constant. Usually, this value is 1.0, but for some problems lower values may help achieve convergence.
DUP. Max Acceleration
This is the max damping value when using the adaptive damping with relative reduced residual.
DLOW. Min Acceleration
This is the min damping value when using the adaptive damping with relative reduced residual.
Conjugate Gradient
Controls whether the conjugate gradient method is used to accelerate the solver. By default this option is on.
Stor1, Stor2, Stor3
These values are ignored in LMG2. In LMG1, these variables are used to control the amount of memory storage used by the solver. The defaults rarely need to be changed.
IOUTAMG. Output control
This controls the information printed to the samg output file while the solver is running.
Reset
This button will change all options to the default state.
| GMS – Groundwater Modeling System | ||
|---|---|---|
| Modules: | 2D Grid • 2D Mesh • 2D Scatter Point • 3D Grid • 3D Mesh • 3D Scatter Point • Boreholes • GIS • Map • Solid • TINs • UGrids |  |
| Models: | FEFLOW • FEMWATER • HydroGeoSphere • MODAEM • MODFLOW • MODPATH • mod-PATH3DU • MT3DMS • MT3D-USGS • PEST • PHT3D • RT3D • SEAM3D • SEAWAT • SEEP2D • T-PROGS • ZONEBUDGET | |
| Aquaveo | ||
