TLNS3D-mb Interface

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The TLNS3D-mb interface writes a map file and a grid file for the multiblocks TLNS3D-mb flow solver. It supports non C0-contiguous interfaces between blocks allowing local refinement. The map file contains a list of terms describing the properties, the turbulence parameters, the dimension and the boundary conditions of each block. The grid file is written in the PLOT3D multiblocks unformatted format with no iblank array.

Creating the TLNS3D-mb map file and grid file

The translator writes the TLNS3D-mb files using the structured domain files (domain.1 to domain.n), the boundary conditions file (boco) and the topology file (topo_mulcad_out). To create the TLNS3D-mb files, select the translator "TLNS3D-mb" in the "Output" menu from the ICEM CFD/CAE Manager. After clicking "Write output" you can specify the following options for the TLNS3D-mb interface:

• select the domains to include in the TLNS3D-mb file
• give the name of the boundary condition file (default is configuration/parts_mesh/mesh/boco)
• give the name of the topology file (default is configuration/topology/topo_mulcad_out)
• give the name of the TLNS3D-mb files

(default map file: configuration/parts_mesh/transfer/configuration.map
default grid file: configuration/parts_mesh/transfer/configuration.dat or configuration.bin)
• option to specify a scaling factor in the x, y and z directions
• option to write the grid coordinates in C-binary or Fortran-unformatted
• option to write the grid coordinates in single or double precision

The interface generates the TLNS3D-mb files located in the Transfer Shell. You may open a shell window in this directory by selecting the menu items "Utility" and "Transfer Shell".

Defining boundary conditions for TLNS3D-mb

In MULCAD, the boundary conditions are defined on subfaces using the "Unspec. Bound. Cond." menu. For a mesh created with the HEXA-Mesher, use the "general bound. cond." menu of the DDN-Mesher Interface. For more details on how to define boundary conditions in MULCAD or in the DDN-Mesher Interface, please refer to the General Remarks section.

Boundary condition types:

The boundary condition types must be assigned on the block faces. After selecting a face, assign the appropriate type by entering one of the name tags listed below. To define a boundary condition type on a singular line, assign the name tag to the corresponding edge. In MULCAD, these names have to be entered at the entry FLAG of the "Unspec. Bound. Cond." menu and in the DDN-Mesher Interface, under the entry string1 of the "general bound. cond." menu.

        MULCAD          DDN-Mesher
        ------          ----------
        1.FLAG          1.string1       Enter the appropriate name tag

If no boundary condition types are defined by the user, the translator assigns automatically:

• type -1 for a cut that patches to another block in a non-C0 fashion (number of points on donor and receiving segments differ).
• type 1 for a cut that maps to another block in a point-to-point match fashion i.e. C0 continuous (number of points on donor and receiving segments match).
• type 7 for a singular line.
• type 99 for an external wall.

The supported boundary condition types are:

        no              name tag        definition
        --              --------        ----------

        -1                              non-C0 interface (set automatically)
        1                ---            C0 interface (set automatically)
        2               SLIP            slip (inviscid) wall
        3               NOSLP           noslip (viscous) wall
        4               SYMM            symmetry condition
        5               DOWNS           downstream/extrapolation condition
        6               FFLD            far-field condition (Riemann invariants)
        7               SGLIN           singular line (set automatically)
        8               FANUP           fan-upstream engine boundary
        9               FANDW           fan-downstream engine boundary
        10              JETNZ           jet-nozzle upstream condition
        99                              external walls (set automatically)

Boundary conditions:

The boundary conditions can be defined on the block faces by specifying the tag PROP and entering the different property values in the order specified here.

        MULCAD          DDN-Mesher
        ------          ----------
        1.FLAG          1.string1       enter the tag PROP
                ...
        3.VALUE         4.real1         enter the value of twotr 
                                        (default is 0.0) 
        4.X             5.real2         enter the value of cq
                                        (default is 0.0) 
        5.Y             6.real3         enter the value of cpor
                                        (default is 0.0) 
        6.Z             7.real4         enter the value of pch
                                        (default is 1.0) 
        7.SCALE         8.real5         enter the value of rad
                                        (default is 0.0) 

        where   twotr:  wall temperature (static) ration (twall/tref)
                cq   :  mass flow rate for blowing/suction
                cpor :  coefficient in wall-porosity b.c. (Darcy/s law)
                pch  :  chamber pressure for Darcy's law for blowing/suction b.c.
                rad  :  specifies radiation b.c., rad=1 is activated, rad=0 is inactive

Limitation

• The interface supports only 3D grids.
• For non C0-continuous interfaces, each cell of the coarse side must correspond to a finite number of cells on the fine side.

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