Pseudo-transient Hydro-Mechanical-Chemical

This repository contains Pseudo-Transient (PT) routines resolving chemical reactions coupled to fluid flow in viscously defroming solid pourous matrix, so-called Hydro-Mechanical-Chemical (HMC) coupling. Example of such multi-physical processes to understand, e.g, the formation of olivine veins by dehydration of ductile serpentinite (Schmalholz et al., 2023), or the brucite-periclase reactions (Schmalholz et al., 2020).

Serpentinite dehydration and olivine vein formation during ductile shearing

Pseudo-Transient approach relies in using physics-motivated transient terms within differential equations in order to iteratively converge to an accurate solution. The PT HMC routines are written using the Julia programming language and build upon the high-performance ParallelStencil.jl package to enable for optimal execution on graphics processing units (GPUs) and multi-threaded CPUs.

Script list

The Julia scripts are located in the scripts folder which contains the routines for the (Schmalholz et al., 2023) study.

The main script is DeHy.jl;
The visualisation script is vizme_DeHy.jl.

Usage

All the routines are written in Julia and can be executed from the Julia REPL, or from the terminal for improved performance. Output is produced using Makie.jl (using the CairoMakie backend).

The either multi-threaded CPU or GPU backend can be selected by adding the appropriate flag to the USE_GPU constant, modifying either the default behaviour in the top-most lines of the codes

const USE_GPU  = haskey(ENV, "USE_GPU" ) ? parse(Bool, ENV["USE_GPU"] ) : false

or by setting/exporting the desired environment variable.

Selecting false will use the Base.threads backend. Multi-threading can be enabled by defining and exporting the JULIA_NUM_THREADS environment variable (e.g. export JULIA_NUM_THREADS=2 prior to launching Julia will enable the code to run on 2 CPU threads).
Selecting true will use the CUDA.jl GPU backend and will succeed if a CUDA-capable GPU is available.

Example running the routine from the REPL

Launch Julia

% julia --project

Activate and instantiate the environment to download all required dependencies:

julia> ]

(PseudoTransientHMC) pkg> activate .

(PseudoTransientHMC) pkg> instantiate

Run the script

julia> include("DeHy.jl")

Example running the routine from the terminal

Launch the Julia executable using the project's dependencies --project:

julia --project DeHy.jl

References

Schmalholz, S. M., Moulas, E., Plümper, O., Myasnikov, A. V., & Podladchikov, Y. Y. (2020). 2D hydro‐mechanical‐chemical modeling of (De)hydration reactions in deforming heterogeneous rock: The periclase‐brucite model reaction. Geochemistry, Geophysics, Geosystems, 21, 2020GC009351. https://doi.org/10.1029/2020GC009351

Schmalholz, S. M., Moulas, E., Räss, L., & Müntener, O. (2023). Shear-driven formation of olivine veins by dehydration of ductile serpentinite: a numerical study with implications for porosity production and transient weakening. https://doi.org/10.1029/2023JB026985

PTsolvers / PseudoTransientHMC.jl