Page 61 - TransAT_Tutorial_Manual

TransAT Tutorial Manual 2.1. Block Mesh Refinement: Flow over Cylinder (Re=150)

Nx: 41 , Cell Ratio : 1.10 , Maximal Ratio : 6
Ny: 31 , Cell Ratio : 1.10 , Maximal Ratio : 6
Nz : 2 , Cell Ratio : 1.00 , 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.

Also note that we will create a BMR grid: the Grid Properties tab only defines the proper-
ties of the coarsest mesh.

Blocks
The Blocks tab will be used to create the block mesh refinement (BMR) and decompose
the domain into several blocks, so that the simulation can run in parallel (i.e. on several proces-
sors). Indeed, each block is allocated to one processor (but a processor can handle several blocks).

With BMR, blocks with finer meshes are created to get a better resolution around areas of
interest.

• Click Blocks

To create a block with a finer mesh around the object

• Click

• Enter the following values in the Add Son Block window then click

X Min : 3.0
X Max: 10.0
Y Min : 4.5
Y Max: 7.5

Now blocks will be split so as to be able to use several processors.
• Select Block 1 by changing the field Select block to 1

• Click then enter the number of blocks in each direction as the following:

X d i r e c t i o n : 2
Y d i r e c t i o n : 1

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