HydroGeoSphere/Interactive Block Grids
Interactive block instructions can be used to generate a grid made up of variably-sized blocks. The user can grade the mesh as desired in each of the 3 principal directions. This is particularly useful for regions in which fine meshes are required, for example, near a discrete fracture or well.
Note that these instructions cannot be used in conjunction with the other grid generation instructions like Generate uniform/variable blocks/prisms.
Generate blocks interactive...End
[edit | edit source]Causes grok to begin reading a group of interactive block instructions until it encounters an End instruction. The group should contain of at least one instruction for each of the principal directions.
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The available instructions are:
Grade x
[edit | edit source]- x1, x2, dxstart, xfac, dxmax Start and end x-coordinate, starting element size,
element size multiplication factor and maximum element size.
Grid lines (i.e. elements) are generated along the x-axis from x1 to x2 which grade up in size from dxstart to dxmax. Element sizes are increased steadily by a factor of xfac.
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Grade y
[edit | edit source]As above but for the y-axis.
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Grade z
[edit | edit source]As above but for the z-axis.
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Example block grid
[edit | edit source]The instructions used to generate the mesh shown in Figure 5.2 are:
generate blocks interactive
grade x
75.0 0.0 0.01 1.5 5.
grade x
75.0 100.0 0.01 1.5 5.
grade x
125.0 100.0 0.01 1.5 5.
grade x
125.0 200.0 0.01 1.5 5.
grade y
100.0 0.0 0.01 1.5 5.
grade y
100.0 200.0 0.01 1.5 5.
grade z
1.0 0.0 0.25 1.0 0.25
grade z
3.0 1.0 0.01 1.3 0.25
grade z
3.0 11.0 0.01 1.3 0.25
grade z
11.0 12.0 0.25 1.0 0.25
end generate blocks interactive