tSimplify and update README - cngf-pf - continuum model for granular flows with pore-pressure dynamics (renamed from 1d_fd_simple_shear)
HTML git clone git://src.adamsgaard.dk/cngf-pf
DIR Log
DIR Files
DIR Refs
DIR README
DIR LICENSE
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DIR commit 5d4a2cef872d8b3cbb45892042bf5df43a0c7616
DIR parent add2fbd712616c5abb67c74ff9626b0f9d4890cb
HTML Author: Anders Damsgaard <anders@adamsgaard.dk>
Date: Tue, 24 Mar 2020 14:14:30 +0100
Simplify and update README
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# 1d_fd_simple_shear
-This project contains a 1d implementation of the [Henann and Kamrin
-2013](https://doi.org/10.1073/pnas.1219153110) model under
-simple shear, with various extensions such as diffusive
-fluid coupling and cohesion. The granular material is
-assumed to be in the critical state with constant porosity. See
-[1d_fd_simple_shear_transient](https://src.adamsgaard.dk/1d_fd_simple_shear_transient)
-for a second version with variable porosity and strength.
-
-## How to run
-The implementation in C requires a C99-compatible compiler (e.g. `gcc`
-or `clang`). Visualization requires `gnuplot`. Tests can be run with
-`make test`, and examples (found in the `examples/` directory) can be
-run with `make examples`.
-
-### Advanced usage
-The majority of simulation parameters can be adjusted from the command line:
-
-```
-usage: 1d_fd_simple_shear [OPTIONS] [NAME]
-runs a simulation and outputs state in files prefixed with NAME.
-If NAME is not specified, intermediate output are not written.
-
-Optional arguments:
- -v, --version show version information
- -h, --help show this message
- -N, --normalize normalize output velocity
- -G, --gravity VAL gravity magnitude [m/s^2] (default 9.81)
- -P, --normal-stress VAL normal stress on top [Pa] (default 120000)
- -m, --stress-ratio VAL applied stress ratio [-] (default 0.45)
- -s, --set-shear-velocity VAL set top shear velocity to this value [m/s]
- (default nan), overrides --stress-ratio
- -l, --limit-shear-velocity VAL limit top shear velocity to this value [m/s]
- (default nan), overrides --stress-ratio and
- --set-shear-velocity
- -V, --velocity-bottom VAL base velocity at bottom [m/s] (default 0)
- -A, --nonlocal-amplitude VAL amplitude of nonlocality [-] (default 0.4)
- -b, --rate-dependence VAL rate dependence beyond yield [-] (default 0.9377)
- -f, --friction-coefficient VAL grain friction coefficient [-] (default 0.404026)
- -C, --cohesion VAL grain cohesion [Pa] (default 0)
- -p, --porosity VAL porosity fraction [-] (default 0.25)
- -d, --grain-size VAL representative grain size [m] (default 0.04)
- -r, --density VAL grain material density [kg/m^3] (default 2600)
- -n, --resolution VAL number of cells in domain [-] (default 100)
- -o, --origo VAL coordinate system origo [m] (default 0)
- -L, --length VAL domain length [m] (default 0.7)
-
-Optional arguments only relevant with transient (fluid) simulation:
- -F, --fluid enable pore fluid computations
- -c, --fluid-compressibility VAL fluid compressibility [Pa^-1] (default 3.9e-10)
- -i, --fluid-viscosity VAL fluid viscosity [Pa*s] (default 0.001787)
- -R, --fluid-density VAL fluid density [kg/m^3] (default 1000)
- -k, --fluid-permeability VAL fluid intrinsic permeability [m^2] (default 1.9e-15)
- -O, --fluid-pressure-top VAL fluid pressure at +z edge [Pa] (default 0)
- -a, --fluid-pressure-ampl VAL amplitude of pressure variations [Pa] (default 0)
- -q, --fluid-pressure-freq VAL frequency of pressure variations [s^-1] (default 1)
- -H, --fluid-pressure-phase VAL fluid pressure at +z edge [Pa] (default 0)
- -t, --time VAL simulation start time [s] (default 0)
- -T, --time-end VAL simulation end time [s] (default 1)
- -I, --file-interval VAL interval between output files [s] (default 0.1)
-
-```
+This project contains a 1d implementation of the Henann and Kamrin
+2013[1] model under simple shear, with various extensions such as
+diffusive fluid coupling and cohesion. The granular material is
+assumed to be in the critical state with constant porosity. A
+transient option with non-constant porosity is under development
+(option -T).
+
+## Compiling and installing
+Requirements are a C99-compatible compiler (e.g. `gcc` or `clang`).
+Run `make` and `make install` to install the programs and their man
+pages.
+
+## Usage
+See `man 1d_fd_simple_shear`, `man max_deformation_depth` and `man
+shear_flux` for usage information.
## Results
+A preprint with model results is publically available[2].
-### Strain distribution
-See below for a comparison with the discrete-element method results from
-[Damsgaard et al. 2013](https://doi.org/10.1002/2013JF002830). The continuum
-model is not tuned rigorously against the DEM, and the correspondence could
-probably be improved further.
-
-| Discrete-element model | Continuum Model |
-| ----------------------- | --------------- |
-| Damsgaard et al. 2013 | |
-|  |  |
-
-### Stress and strain rate
-The rheology is of Bingham type, where no deformation occurs beneath the
-Mohr-Coulomb yield limit. Above it, deformation is highly non-linearly viscous.
-The model has a parameter *b* for rate dependence beyond yield. Glass beads
-have *b* = 0.94 ([Forterre and Pouliquen
-2003](https://doi.org/10.1017/S0022112003004555)).
-
-| Real material (laboratory or field study) | Continuum Model |
-| -------------------------------------------- | --------------- |
-| Upstream-B ([Kamb 1991](https://doi.org/10.1029/91jb00946)): | |
-|  |  |
-| Various subglacial tills ([Iverson 2010](https://doi.org/10.3189/002214311796406220)): | |
-|  |  |
-| Whillans Ice Plain ([Tulaczyk 2006](https://doi.org/10.3189/172756506781828601)): | |
-|  |  |
-
-### Variable water pressure
-The model is expanded from the Henann and Kamrin 2013 model by including a
-diffusive porewater pressure parameterization. Below is an example of diurnal
-water-pressure variations that gradually propagate into the bed.
+## Author
+Anders Damsgaard <anders@adamsgaard.dk>
+https://src.adamsgaard.dk/1d_fd_simple_shear
+ISC licensed, see LICENSE for details.
-
+## References
+[1]: https://doi.org/10.1073/pnas.1219153110
+[2]: https://arxiv.org/abs/2002.02436