Keyword POUTRE_FLUI ==== Syntax ---- POUTRE_FLUI = _F ( ♦ GROUP_MA = lgma, [l_gr_mesh] ♦ B_T = bt, [real] ♦ B_N = bn, [real] ♦ B_TN = btn, [real] ♦ A_FLUI = false, [real] ♦ A_CELL = acell, [real] ♦ COEF_ECHELLE = ech, [real] )))) Affordable characteristics ---- This factor keyword makes it possible to define the characteristics of the finite elements (hexahedron with 8 or 20 nodes) associated with the '3D_FAISCEAU' modeling, cf. the command AFFE_MODELE [U4.41.01]. This modeling concerns the representation of a periodic network of tubes bathed by an incompressible fluid [:ref:`R4.07.05 `]. An example is given in test SDLV111 [V2.04.111]. Operand GROUP_MA ---- Place of assignment of basic characteristics: • list of mesh groups (keyword GROUP_MA). Operands A_FLUI/A_CELL/COEF_ECHELLE ---- +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------+ |The periodic cell of the medium to be homogenized is two-dimensional. | | + + .. image:: images/100000000000016C00000138C4AD75FD9AC02E0B.png + | The basic periodic cell that is used to calculate the homogenized coefficients is obtained by homothety from the real periodic cell in the medium. | :width: 2.1965in | + + :height: 1.8165in + | | | + + + | | | +---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+-----------------------------------------------------------------------------------------------------------------------------+ ♦ A_FLUI: Area of the part occupied by the fluid in the basic periodic cell ♦ A_CELL: Area of the basic periodic cell ♦ COEF_ECHELLE: Homothety coefficient to transform the real periodic cell into the basic periodic cell Operands B_T/ B_N/ B_TN ---- Homogenized coefficients of the fluid-structure problem calculated in frame :math:`(T,N)` [:ref:`R4.07.05 `]. The orientation of this coordinate system is set by the keyword factor ORIENTATION. Direction :math:`L` is necessarily parallel to the axis of the tube bundle. .. _RefHeading__31252906: