Flownet update

This is a revised version of the last flownet generation program.

Changes:

• Head at dam heel is equal to the impounded water depth as should be(was assumed 0 before)
• Dam was fixed to be the size of a single grid box. Now, width of dam can be specified
• Dam's heel and toe are Dirichlet boundaries i.e. known heads but any node between are treated as unknowns
• Better code documentation during coefficient matrix construction.

The code file is 'Source1V2.f90'

My sketches for this revision.

An associated Excel spreadsheet for control.

Some more screenshots:

Flownet of the original problem with numDxs=4,numDys=3,DxsTillDam=2,DamWidthInDxs=2,reservoirHead=100,downstreamBoundaryHead=50 and contourInterval=10

Flownet of a problem with numDxs=5,numDys=5,DxsTillDam=2,DamWidthInDxs=3,reservoirHead=100,downstreamBoundaryHead=50 and contourInterval=10

Flownet of a problem with numDxs=15,numDys=15,DxsTillDam=5,DamWidthInDxs=3,reservoirHead=100,downstreamBoundaryHead=50 and contourInterval=5

The weird aggregation of isobars at the right(downstream) boundary between 0 and 50m is because of the type of boundary condition given. A constant head (50m) Dirichlet boundary in the vertical direction is unrealistic. An impermeable vertical plane (Neumann boundary) would have allowed a smooth and probably more realistic variation of head downstream.