Difference between revisions of "CapillaryTriaxialTest"
From Yade
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== Modelling granular materials with capillary forces == |
== Modelling granular materials with capillary forces == |
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| − | Capillary effects are taken into account as a result of capillary bridges between each pair of spherical elements based on the resolution of the Laplace-Young equation. Be careful, the formulation is valid only for pendular menisci involving two grains (the so-called "pendular regime"). At the scale of an assembly, the corresponding degrees of saturation are therefore limited to low values (typically, between 0 and 15%). An algorithm has been developed by B. Chareyre to identify menisci overlaps on each spheres (menisci fusion). Some basic assumptions can be made to reduce capillary forces when menisci overlap (binary->Fcap=0 if at least 1 overlap, linear->Fcap=Fcap/numberOfOverlaps), but this is purely experimental. |
+ | Capillary effects are taken into account as a result of capillary bridges between each pair of spherical elements based on the resolution of the '''Laplace-Young equation'''. Be careful, the formulation is valid only for pendular menisci involving two grains (the so-called '''"pendular regime"'''). At the scale of an assembly, the corresponding degrees of saturation are therefore limited to low values (typically, between 0 and 15%). An algorithm has been developed by B. Chareyre to identify menisci overlaps on each spheres (menisci fusion). Some basic assumptions can be made to reduce capillary forces when menisci overlap (binary->Fcap=0 if at least 1 overlap, linear->Fcap=Fcap/numberOfOverlaps), but this is purely experimental. |
| − | The control parameter is the capillary pressure (or suction) Uc, defined as the difference between gas and liquid pressure: Uc = Ugas - Uliquid. Liquid bridges properties (capillary Force Fcap, volume V and extents over interacting grains delta1 and delta2) are computed as a result of the defined Uc and the interacting geometry (spheres radii and interparticular distance). |
+ | The control parameter is the '''capillary pressure''' (or suction) Uc, defined as the difference between gas and liquid pressure: Uc = Ugas - Uliquid. Liquid bridges properties (capillary Force Fcap, volume V and extents over interacting grains delta1 and delta2) are computed as a result of the defined Uc and the interacting geometry (spheres radii and interparticular distance). |
| − | For more documentation, have a look to: |
+ | For more '''documentation''', have a look to: |
1 - L. Scholtes, PhD thesis -> https://tel.archives-ouvertes.fr/tel-00363961/en/ (a lot of details but in french) |
1 - L. Scholtes, PhD thesis -> https://tel.archives-ouvertes.fr/tel-00363961/en/ (a lot of details but in french) |
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2 - L. Scholtes et al. Micromechanics of granular materials with capillary effects. International Journal of Engineering Science 2009,(47)1, 64-75 |
2 - L. Scholtes et al. Micromechanics of granular materials with capillary effects. International Journal of Engineering Science 2009,(47)1, 64-75 |
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| − | To run the simulations, you have to download this [[File:Capillary.gz]] and extract the content to your yade/bin folder (where the yade executable is). You should end with 10 text files in /bin. CapillaryLaw will read those files once at startup and use the data to interpolate capillary forces for arbitrary cases. |
+ | '''To run the simulations''', you have to download this [[File:Capillary.gz]] and extract the content to your yade/bin folder (where the yade executable is). You should end with 10 text files in /bin. CapillaryLaw will read those files once at startup and use the data to interpolate capillary forces for arbitrary cases. |
Revision as of 09:13, 23 April 2010
Modelling granular materials with capillary forces
Capillary effects are taken into account as a result of capillary bridges between each pair of spherical elements based on the resolution of the Laplace-Young equation. Be careful, the formulation is valid only for pendular menisci involving two grains (the so-called "pendular regime"). At the scale of an assembly, the corresponding degrees of saturation are therefore limited to low values (typically, between 0 and 15%). An algorithm has been developed by B. Chareyre to identify menisci overlaps on each spheres (menisci fusion). Some basic assumptions can be made to reduce capillary forces when menisci overlap (binary->Fcap=0 if at least 1 overlap, linear->Fcap=Fcap/numberOfOverlaps), but this is purely experimental.
The control parameter is the capillary pressure (or suction) Uc, defined as the difference between gas and liquid pressure: Uc = Ugas - Uliquid. Liquid bridges properties (capillary Force Fcap, volume V and extents over interacting grains delta1 and delta2) are computed as a result of the defined Uc and the interacting geometry (spheres radii and interparticular distance).
For more documentation, have a look to:
1 - L. Scholtes, PhD thesis -> https://tel.archives-ouvertes.fr/tel-00363961/en/ (a lot of details but in french)
2 - L. Scholtes et al. Micromechanics of granular materials with capillary effects. International Journal of Engineering Science 2009,(47)1, 64-75
To run the simulations, you have to download this File:Capillary.gz and extract the content to your yade/bin folder (where the yade executable is). You should end with 10 text files in /bin. CapillaryLaw will read those files once at startup and use the data to interpolate capillary forces for arbitrary cases.