Manual pages | Cast3M

$$$$ KMBT     NOTICE  CHAT      11/09/12    21:16:45     7124           
                                             DATE     11/09/12
                                                                                
    Operateur KMBT                           Voir aussi : NAVI KMAB
    --------------                                        KBBT   DUDW   
                                                          EQEX    
    SYNTAXE ( EQEX ) :   Cf operateur EQEX                 
    __________________

      'OPER'  'KMBT' coef      'INCO' 'UN' 'PRES'


                                                                                
                                                                                
     Description :
     _____________

 The KMBT operator discretizes the Grad P  term of the Navier-Stokes
equation by a finite element method.


     Contents :
     __________

     coef    coefficient
             FLOTTANT
             or CHPOINT SCAL SOMMET  (volumic porosity)
             or CHPOINT VECT SOMMET  (directional porosity)
             or MOT

     UN      Velocity field
             CHPOINT VECT SOMMET or MOT
     PRES    Pressure field
             CHPOINT SCAL CENTRE   or MOT
             CHPOINT SCAL CENTREP1 or MOT
             the type has to be given with the option key word INCOD

  When coefficients are of type MOT, the operator looks for data in INCO
  table at the index corresponding to the given name.





    Comments
    ________

  1/ Associated boundary conditions :

 In the variational formulation the term  'Grad P' is integrated by part
 and then using the divergence theorem we get :

   /                /          /
   | W*Grad P dv =  | P n ds - | P Div W dv
   |v               |s         |v

 The surface integral is ommited which leads to the natural induced
 boundary condition:

   /
   | P n ds = 0   (n outward normal)
   |s

 Additional induced boundary conditions can appear whith other operator
 like LAPN.
 See operator TOIM in order to impose a value to the surface integral.

  2/ If the coefficient is of type CHPOINT SCAL SOMMET
    (volumic porosity H) the operator computes :

   /                  /            /                 /
   | W*H*Grad P dv =  | WHP n ds - | P H Div W dv  - | P W Grad H  dv
   |v                 |s           |v                |v


  3/ If the coefficient is of type CHPOINT VECT SOMMET
    (directional Porosity Hi ) the operator computes :

   /                   /              /                  /
   | W*Hi*Grad P dv =  | WHi P n ds - | P Hi Div W dv  - | P W Grad Hi dv
   |v                  |s             |v                 |v



    Options : (EQEX)
    _________

    OPTI INCOD CENTRE
               CENTREP1