FEHM Version 3.6.2

This release includes improved phase change algorithms, saved zone usage, and boundary conditions primarily related to new isothermal two-phase flow with dissolved gas. Also updated zone_saved capability.

Code enhancements are generally related to improvements in numerical performance for the AMANZI isothermal, 2-phase, noncondensible, gas-water physics with gas solubility. Included are subroutine changes to accommodate restarts with the new AMANZI physics.

• Added variables for global gas and dissolved gas, added cnlof() for last times step dissolved gas

• Added tolerances for phase change, improved phase change (dissolved gas) algorithm

• Changed VG upper/lower cutoff parameters

• Added code to read and output isothermal multiphase solubility variables

• Added new subroutine geneq2_sol to generate equations for iso 2phase with sol

• Added use module com_prop_data (for future use)

• Added new subroutine inpress_solubility to read variables associated with isothermal two phase w solubility; added old mass fraction cnlof() set to cnlf()

• Modified code so initial liquid mass fraction is not read in ‘air’ keyword but in ‘pres’ keyword

• Added coding to set phase state(ieos) based on initial conditions (including iso 2phase w sol)

• Modified boundary condition (kq = -202), corrected but in solubility calculation

• Modified code so upper cutoff is passed through subroutine header

• Some code corrections for simulations related to VV Test cases and how output files are written.

• Documentation has been changed from sphinx to github pages for easier updates. Missing pages and sections have been fixed. fehmpytests descriptions and instructions have been added.

• This release was compiled and tested primarily on Windows using VisualStudio, Linux with GCC 9.4 and 13.2, and mac OSX compiled on GCC 13.2

See full Release Notes at https://lanl.github.io/FEHM/references-support/ReleaseNotes/v3.6.2/

FEHMPYTESTS is included in this repo and is recommended for developers as a fast, easy to use set of test cases to verify correctness of the code. This does not replace the VV Test Suites used since the YMP QA program in 2003, but is easier to use and faster to run. Most the test cases were constructed from the VV Test Suite and have the same input and output files.
See test descriptions at https://lanl.github.io/FEHM/fehmpytest-info/testdesc

The VV Test Suite is still used for checking analytical solutions and comprehensive multi-run models. The perl scripts and programs it uses may have problems running, but the test problems can still be run and results evaluated manually. The Windows version V3.4 of the VV Test Suite has been improved and is successful with this release. The Linux version 3.3 has not been updated but was used for testing this release. Both VV Test Suites are available as assets with this release, see VERIFICATION_V3.4win_v3.6_clean.tar.gz and VERIFICATION_V3.3.0lnx_V3.6_clean.tar.gz

FEHM-mars

Mars-specific branch of FEHM.

Working example located in:

/FEHM/example

Contributors:
@johnportiz14

FEHM Version 3.4.0 - September 2019

The major changes in the FEHM application from V3.3.1 to this release V3.4.0 are: salt and GDKM development, various modifications to improve the performance of FEHM simulation, fixing several known code bugs, and salt_test in V&V test suite was updated with improved theoretical solution (theoretical_result.txt).

Enhancements include:

• Nonlinear rock heat capacity including rock melting. This capability allows the rock heat capacity with temperature dependence to be used in simulations. The numerical formulation for rock energy was modified to allow internal energy changes that represent rock melting. Several different heat capacity/melting models are available including input in tabular form. This capability will be fully tested and input/output described when the High Temperature version of FEHM is merged in the next release.

• Negative volume. A simple check for negative volumes associated with inconsistent local element node ordering was implemented.

• Humidity boundary conditions. Humidity boundary conditions were added to the BOUN macro.

• Gravity term correction. There are instances in multiphase simulations where a single phase gridblock is next to a multiphase block. In this case, it is possible that the density of one of the phases is not calculated for the single phase block. This affects the gravity term and is now corrected. (Seems to save a few iterations.) First discovered in TOUGH code at the University of Auckland.

• Salt project. Modified several of the salt routines. These changes were primarily for improvements to output. There are some computational efficiency improvements (saltctr).

• SRC_CH2017 (general). Moved vapor pressure lowering calls and improved the free drainage boundary condition for isothermal flow.

• Principal stress output. Changes the output for principal stress. Moved some arrays to use modules for improved efficiency.

• Saved Zone capability. This allows zones to be saved once and for all. This allows sets of zones not to lose nodes because of overlapping nodes defined sequentially. Useful for setting stratigraphy and boundary conditions and for outputting separate contour zones.

• GDKM. This is a major update to the GDKM capability. Corrected known bugs, simplified input, and added models. The models include the

FEHM Version 3.3.1 September 2017

The major changes in the FEHM application from V3.3.0 (2015) to this release V3.3.1 are: further developments for macros SALT and RPL/RLPM. Improvements added related to TRXN, CDEN and CO2 coupling with tracers. GDKM input was modified to have a general formulation equivalent to DPDP and direction-specific fracture formulation. New humidity related boundary conditions were added to BOUN including HUF (flowing humidity), HU (fixed humidity), TH (humidity temperature), and PH (humidity pressure). Minor code modifications were made to improve the performance of FEHM simulations.

Known code bugs fixed:

1. Fix the pressure BC issue (remember to use PA in BOUN)
2. Fixed phase change guess with low water vapor pressure.
3. Minor fixes to improve read/write of various files and the handling of input parameters.
4. Change in startup.f resolved a simulation result discrepancy between AMANZI/analytical solution and FEHM.
5. All V3.* versions of FEHM will report negative coupling coefficients if they exist. The older V2 releases do not report on coupling coefficients. This difference in reporting is not a bug in either release, just a difference in the information that is written.

Known issues:

1. Macro DVA has a forced explicit update to fix possible derivative problems, needs further checking.
2. The vector files written for contouring are the control volume interface volumetric flux values mapped back on to the mesh nodes. The algorithm for this mapping will have errors most visible for non-orthogonal meshes.
3. This mac test suite was created on Mavericks and some comparison binary files are no longer compatible with OS Yosemite or newer. For these tests, results need to be checked and compared individually. FEHM V3.1.1 results were checked and all tests passed.

(https://github.com/lanl/FEHM/files/1794851/FEHM_V3.3.1_release_summary.pdf)

FEHM Version 3.3.0 December 2015

The major changes in the FEHM application from V3.2.0 to this release V3.3.0 are: enhancements related to multi-phase flow physics in salt, updates to stress capabilities, and modifications to improve the performance of FEHM simulations such as air-water-heat physics module. (Refer to Appendix V3.3.0 in the User Manual). Enhancements to this release include:

New salt simulation capabilities such as the ability to run salt simulations with combinations of water vapor formulations, initialization of grid blocks to saturation temperature at total fluid pressure or total fluid pressure at saturation temperature, improved numerical performance with temporal averaging of porosities permeabilities.

Enhancements to air-water-heat physics module with the "ngas" keyword that improve performance of FEHM when simulating the drying out of rock.

Enhancement to stress capabilities include new rock failure model that applies Mohr-coulomb failure criteria to an ensemble of fractures with variable orientations.

macro "bodyforce" adds flexibility for specifying body forces so user can apply body force on each node.
macro "cont" has new keyword "heatflux" which prints the x,y,z heat flux vector (W/m2) analogous to the velocity vector.
macro "boun" has new keyword "fxa" for handling the boundary conditions for air-water-heat physics.

Known code bugs fixed:

1. Modification to dvacalc.f to fix a bug in setting the limits of dva.
2. diagnostics.f: Fixed array accessing error that stopped code on some platforms.
3. Code change to exponential.f to avoid NaN problem.
4. write_avs_node_con.f: Fixed contour output problems for vapor species, and array out of bound problems.

There are No known bugs in this V3.3.0 release

The platforms compiled for FEHM V3.3.0 release are:
Linux Ubuntu (64-bit): compiled with gfortran 4.8.2
Linux RedHat 5 (64-bit): compiled with gfortran 4.5.1
MAC OSX (Mavericks 10.9): compiled with gfortran 4.9.0
PC Windows (32-bit and 64-bit): compiled with Intel Parallel Studio XE 2011

FEHM_UM_V3.3.0.pdf

FEHM Version 3.2.0 July 2013

The major changes in the FEHM application from V3.1 to this release V3.2, are improvements to geothermal, CO2, and stress capabilities. All changes are described in detail in release notes and Appendix documents posted on fehm.lanl.gov web page. Enhancements to this FEHM release include:

Additional stress models have been added, including stess permeability for shear-stimulated fractures and settings for incremental shear for porosity damage.

Enhanced functionality for C02 problems have been added. The User Manual documentation has been updated for both "carb" and "grad". Output for macro "rlpm" has been generalized to include both co2 gas /water and co2 liquid /water output.

For mass, energy balances in porous media, "anpe" (anisotropic permeability) has been modified to work with dual or dpdp or gdpm or gdkm for the isothermal case. The macro "anpe" works with "trac" for transport and "gdkm" works with isothermal and thermal.

The macro "trxn" is a new macro, which does not add functionality but is a user-friendly interface to "trac" and "rxn".

The platforms compiled for FEHM V3.2.0 release are:
Linux RedHat 5 (64-bit): compiled with gfortran 4.5.1
MAC OSX (Mountain Lion 10.8): compiled with gfortran 4.8.1
PC Windows (32-bit and 64-bit): compiled with Intel Parallel Studio XE 2011

FEHM_documents.tar.gz

FEHM Version 3.1.0 April 2012

This version brings current all code work since January 2008 and includes the internal release V3.0 on which must of the User Manual was based. The FEHM copyright for FEHM LA-CC-2012-083 was based on this version of code.
README.txt

Release_notes_V3.1.0.txt