Data part, prepare post-processing

post_calcul -groundflow_pressure -total_pressure
post_node 0 -node_rhside -sum -left_edge

The post_calcul record takes care of calculating extra post-processing data. This calculated data becomes available for printing or for plotting in Gid. See the user's manual for all possibilities of post_calcul. Here post_calcul is used to calculate the total pressure (=pore pressure); remember that primarily the hydraulic head is calculated in a groundflow analysis, so that the total pressure is only available as extra post processing option.

The post_node records are a convenient method to determine in structural calculations forces on prescribed displacement edges, or here in a groundflow calculation the groundwater flux to the environment. Using post_node 0 -node_rhside -sum -left_edge as shown here, causes the right-hand-side to be summed over all nodes which are located in the geometry -left_edge. The result will be placed in the record post_node_result, which can be printed during the calculation or found in the database after the calculation. You find in post_node_result the required flux at the position consistent with the initialized groundwater pressure variable. Look in dof_label after the calculation: there you see that the first variable is the hydraulic head -pres, and thus you find the groundwater flux also at the first position in the post_node_result record.