Discretization
==============


Degrees of freedom
------------------


.. csv-table::

    "**Finite element**", "**Degrees of freedom (at each vertex node)**"



.. csv-table::

    "MEFL_xxx (3D_ FLUIDE)", "PRES: pressure
    PHI: potential for fluid movement"
    "MEFL_FACE (3D_ FLUIDE)", "PHI: fluid displacement potential"
    "MEFS_xxx (FLUI_STRU)", "DX, DY, DZ: structural displacement components
    PHI: potential for fluid movement"
    "MEFP_FACE (2D_ FLUI_PESA)", "DZ: free surface deflection
    PHI: potential for fluid movement"



Support mesh for stiffness matrices
------------------------


.. csv-table::

    "**Modeling**", "**Mesh**", "**Finished Element**", "**Remarks**"



.. csv-table::

    "3D_ FLUIDE "," TETRA4 "," "," MEFL_TETRA4 ", ""
    "", "TETRA10 "," MEFL_TETRA10 ", ""
    "", "PENTA6 "," MEFL_PENTA6 ", ""
    "", "PENTA15 "," MEFL_PENTA15 ", ""
    "", "HEXA8 "," MEFL_HEXA8 ", ""
    "", "HEXA20 "," MEFL_HEXA20 ", ""
    "", "HEXA27 "," MEFL_HEXA27 ", ""
    "FLUI_STRU "," TRIA3 "," MEFS_FACE3 ", ""
    "", "TRIA6 "," MEFS_FACE6 ", ""
    "", "QUAD4 "," MEFS_FACE4 ", ""
    "", "QUAD8 "," MEFS_FACE8 ", ""
    "", "QUAD9 "," MEFS_FACE9 ", ""
    "2D_ FLUI_PESA "," TRIA3 "," MEFP_FACE3 ", ""
    "", "TRIA6 "," MEFP_FACE6 ", ""
    "", "QUAD4 "," MEFP_FACE4 ", ""
    "", "QUAD8 "," MEFP_FACE8 ", ""
    "", "QUAD9 "," MEFP_FACE9 ", ""


**Note 1:**

*Coupling with a mesh structure of elements* *COQUE_3Dimpose to mesh the fluid-structure interface with elements* *QUAD8 (and not* *QUAD9) elements. The fluid massive domain is therefore meshed in* *HEXA20 (and not* *HEXA27). In fact, fluid-structure coupling takes place on the degrees of freedom of movement only, for the solid.*

 **Note 2:**

*It is imperative that the normal outside the fluid domain is always oriented from the fluid to the structure, for all fluid-structure interface models, in particular* *FLUI_STRU.*


Cargo support mesh
------------------------------


.. csv-table::

    "**Modeling**", "**Mesh**", "**Finished Element**", "**Remarks**"



.. csv-table::

    "3D_ FLUIDE "," TRIA3 "," "," MEFL_FACE3 ", ""
    "", "TRIA6 "," MEFL_FACE6 ", ""
    "", "QUAD4 "," MEFL_FACE4 ", ""
    "", "QUAD8 "," MEFL_FACE8 ", ""
    "", "QUAD9 "," MEFL_FACE9 ", ""
    "2D_ FLUI_PESA "," TRIA3 "," MEFP_FACE3 ", ""
    "", "TRIA6 "," MEFP_FACE6 ", ""
    "", "QUAD4 "," MEFP_FACE4 ", ""
    "", "QUAD8 "," MEFP_FACE8 ", ""
    "", "QUAD9 "," MEFP_FACE9 ", ""