HydroGeoSphere/Time-Varying Inputs

To define more complex spatial and temporal properties for a boundary condition use:

Time value table

1. bc_time(i), bc_val(i)...end The time and boundary condition value list.

At time bc_time(i) the value bc_val(i) is applied and maintained until time bc_time(i+1). The last value entered in the list will be applied until the end of the simulation.

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Time raster table

1. bc_time(i), bc_raster(i)...end The time and raster file name list.

At time bc_time(i) the raster file bc_raster(i) is applied and maintained until time bc_time(i+1). The last raster file entered in the list will be applied until the end of the simulation. HydroGeoSphere uses the node (or face centroid) xy-coordinate for each member of the set to interpolate a value for the boundary condition at that point.

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The following instructions use the same input data structure except they are applied to xz- or yz- coordinates:

time raster xz table

time raster yz table

Time file table

1. bc_time(i), bc_file(i)...end The time and file name list.

At time bc_time(i) the values read from file bc_file(i) are applied and maintained until time bc_time(i+1). The data from the last file entered in the list will be applied until the end of the simulation. HydroGeoSphere reads a list of values from the file and assigns them in order to the current set of nodes or faces, depending on what type of boundary condition is being applied. The number of values in the file must match the number of nodes or faces in the set or grok will stop with an error message.

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This instruction can be used in conjunction with other instructions to create files of nodal values and then read them in to define boundary conditions. For example, these instructions:

    clear chosen nodes
    choose nodes x plane
    0.0
    1.e-5

    nodal function z to file
        inflow.txt
        ! Z   value
         0.0   0.
         3.   10.
        10.    4.
    end

    create node set
    inflow

create a file inflow.txt which contains a value for each currently chosen node. It uses the nodal z-coordinate to interpolate the value from the tabulated function of z versus value. We can now use the file like this:

boundary condition
    type
    head

    node set
    inflow

    time file table
    0.0   inflow.txt
    11.   none
    end

end ! new specified head

Note that we use the node set inflow in conjunction with the file inflow.txt. Any mismatch in the number of nodes between the node set file and the data file will cause grok to stop with an error message.