... | ... | @@ -4,9 +4,9 @@ It is important to note that within the granular flows field there are many diff |
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The MigFlow software can take into account friction between the grains in various ways.
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Its own frictional contacts solver, _scontact_, can solve friction in both 2D and 3D for spherical grains, considering that they can rotate or not. This local solver takes advantage of the sphericity of the particles to be very fast and efficient. The forces exerted by the grains on the domain boundaries can be computed, as well as the stress tensor inside the grains. Finally, _scontact_ allows to fix some grains so that they act like a boundary, enabling the simulation of a granular flow through a fixed porous media for example.
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Its own frictional contacts solver, _scontact_, can solve friction in both 2D and 3D for spherical grains, considering that they can rotate or not. This local solver takes advantage of the sphericity of the particles to be very fast and efficient. The forces exerted by the grains on the domain boundaries can be computed, as well as the stress tensor inside the grains. It is also possible to set periodic conditions at the boundaries. Finally, _scontact_ allows to fix some grains so that they act like a boundary, enabling the simulation of a granular flow through a fixed porous media for example.
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Another possibility is to use [LMGC90](https://git-xen.lmgc.univ-montp2.fr/lmgc90/lmgc90_user/wikis/home) Software (for installation we recommend to follow the instructions on their website), which is compatible with the fluid solver of MigFlow. This way, more complex contact laws and particle shapes can be taken into account.
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Another possibility is to use [LMGC90](https://git-xen.lmgc.univ-montp2.fr/lmgc90/lmgc90_user/wikis/home) Software (for installation we recommend to follow the instructions on their website), which is compatible with the fluid solver of MigFlow. This way, more complex contact laws and particle shapes can be taken into account. Note that the fluid solver will always consider spherical shapes for the grains.
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Both solvers make use of the Nonsmooth Contact dynamics, which is a time-stepping method that corrects iteratively the free velocities of the grains, obtained by applying external forces, to compute a set of velocities giving after displacement of the grains a stationary state without intersection.
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Some test cases are given to present how to call LMGC90 from the Users Interface:
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... | ... | @@ -32,3 +32,9 @@ fluid.adapt_mesh(Max. element size, Min. element size, Total number of elements, |
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To consider two continuous phases, an advective equation for the concentration is added to the standard Navier-Stokes equations. See the following example to run test cases with two different continuous phases.
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- [avalanch2fluids.py](https://git.immc.ucl.ac.be/fluidparticles/migflow/blob/master/testcases/avalanch/avalanch2fluids/avalanch2fluids.py) presents the fall of a granular column immersed in sea water in a 2D domain filled with soft water.
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### Free surface
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A free surface whose resolution is based on an Arbitrary Lagrange-Euler (ALE) method can be simulated. The following testcase makes use of this feature:
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- [poiseuille.py] (https://git.immc.ucl.ac.be/fluidparticles/migflow/blob/master/testcases/poiseuilleALE/poiseuille.py) presents the swelling of a flow past a die in 2D. |