Page 345 - TransAT_Tutorial_Manual

TransAT Tutorial Manual 8.1. Flow around a train entering a tunnel

8.1.6 Mesh & BCs Tab

In the Mesh & BCs tab, the domain along with the mesh are defined.

• Select Mesh & BCs at the top of the TransATUI window

Domain & Grid Tab
In this section the domain and the computational grid for the simulation will be defined.
• Select the Domain & Grid tab

• In the Domain section, set the following values for the boundaries

X min [m] : −1.2
X max [m] : 1.2
Y min [m] : 0.0
Y max [m] : 0.06
Z min [m] : −0.001
Z max [m] : 0.001

You can click at the bottom of the graphical window to display the domain in the XY plane.

• Set the values of the grid parameters as follows to define the cell density in the domain and
the refinement zones.
Nx: 441 , Cell Ratio : 1 , Maximal Ratio : 1.10
Ny: 26 , Cell Ratio : 1 , Maximal Ratio : 1.10
Nz : 2 , Cell Ratio : 1 , Maximal Ratio : 1

Note that Nx, Ny, Nz are the number of corner points in the x, y and z directions. The actual
number of cells in each direction is the number of corner points in the corresponding direction
minus one.

Blocks
The domain must now be decomposed into several blocks, so that the simulation can run in
parallel (i.e. on several processors). Indeed, each block is allocated to one processor (but a
processor can handle several blocks).

• Select Blocks to define the multiblock option.

• Click to split the domain into several computational blocks.

• Set the number of blocks for the X direction to 2 then click

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