Session 4A

Session 4A - Water Flow to a Stream 1

• Project Manager Button ”New”
  Name: plume1
  Description: Water flow to a stream - 1
  Button ”Open”

• Main Processes Heading: Water flow to a stream - 1
  Button ”Next”

• Geometry Information Type of Flow: Vertical Plane
  Geometry Type: General
  Number of materials: 1
  Length Units: cm
  Button ”Next”

• Time Information Time Units: Days
  Final time: 100
  Initial Time Step: 0.001
  Minimum Time Step: 0.00001
  Maximum Time Step: 5
  Button ”Next”

• Print Information Check All Number of Print Times: 6
  Button "Select Print Times": 1 5 10 25 50 100
  Button ”Next”

• Water Flow - Iteration Criteria Water content tolerance: 0.0005
  Pressure head tolerance: 1
  Lower Limit of the Tension Interval: 0.001
  Upper Limit of the Tension Interval: 1000
  Button ”Next”

• Water Flow - Soil Hydraulic Model Button ”Next”

• Water Flow - Soil Hydraulic Parameters Catalog: Loam
  Button ”Next”

• Meshgen-2D: Geometry
  Window Coordinates: X=2500, Y=250, Width= 6000, Hight=600
  Set view Stretching factors according to given extents
  Menu: Tools->Grid Setting: Width = 100, Hight = 20
  Enlarge Window to entire screen
  Menu: Insert->Line->Graphically
  Menu: Insert->Spline->Graphically
  Menu: View->Stretching->In Y Direction: 0.2
  Save
   

Notice that units in this figure are in meters, and thus have to be converted to cm

• Meshgen-2D: Boundary Points
  Toolbar Button: ”Edit Boundary Points”
  Button ”Number of Boundary Points”: 500
  Nodal Density:
   

Save

• Meshgen-2D: FEM Mesh
  Toolbar Button: ”Edit FEM Mesh”
  Button: Make mesh
  Save
  Exit

• The BOUNDARY Module:
  • Initial Condition:
    Toolbar Button: ”Initial Condition”
    Button "Select": Select the entire transport domain between x=0cm and 400 cm Button "Set Value": check "equilibrium from the lowest located nodal point." And set equal to 350.
    Ditto for x=(400,1000), h=300
    Ditto for x=(1000,1600), h=250
    Ditto for x=(1600,3300), h=200
    Ditto for x=(3300,5000), h=175
  • Water Flow Boundary Conditions: Toolbar Button: ”Water Flow BC”
    • Select "Constant pressure", select left side boundary, specify 400 cm with equilibrium from the lowest located nodal point.
    • Ditto for the right side boundary with h=190 cm with equilibrium from the lowest located nodal point. Zoom on the stream
    • Ditto for stream: nodes with z coordinate smaler than 175 cm, h=80 cm with equilibrium from the lowest located nodal point. Zoom on the slope left of the stream
    • Select "Seepage face": nodes left of stream with z coordinate smaller then 300 cm.
  • Toolbar Button: ”Default View”
    Save
    Close

• Execute HYDRUS
  (Execution time on P5-300 = 534)

• OUTPUT:
  Menu: Post-Processing -> Graphical Display of Results
  Pressure heads
  Water contents
  Velocities