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 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. • • • The available instructions are: Grade x 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. • • • Grade y As above but for the y-axis. • • • Grade z As above but for the z-axis. • • • Example block grid 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 Figure 5.2thumb|none|600px|Figure 5.2: Example Grid which was Created Using Generate blocks interactive Instructions