14. Keyword POUTRE_FLUI#

14.1. 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]

14.2. 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 [R4.07.05]. An example is given in test SDLV111 [V2.04.111].

14.3. Operand GROUP_MA#

Place of assignment of basic characteristics:

  • list of mesh groups (keyword GROUP_MA).

14.4. Operands A_FLUI/A_CELL/COEF_ECHELLE#

The periodic cell of the medium to be homogenized is two-dimensional.

The basic periodic cell that is used to calculate the homogenized coefficients is obtained by homothety from the real periodic cell in the medium.

 _images/100000000000016C00000138C4AD75FD9AC02E0B.png

♦ 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

14.5. Operands B_T/ B_N/ B_TN#

Homogenized coefficients of the fluid-structure problem calculated in frame \((T,N)\) [R4.07.05].

The orientation of this coordinate system is set by the keyword factor ORIENTATION. Direction \(L\) is necessarily parallel to the axis of the tube bundle.