HydroGeoSphere/Tile Drains
Tile drains, as outlined in Section 2.3.2.3, can be set up using the following instructions. Currently, this option requires that the system be variably-saturated.
Default Tile Drain Properties
editThe default tile drain values, Table 5.9, can be and are recommended to be modified to fit the model application.
Parameter | Value | Unit |
---|---|---|
Screen Radius | 1 × 10−5 | m |
Coupled Conductivity | 7.438 × 10−5 | m s−1 |
Coupled Length | 1 × 10−4 | m |
Coupled Scheme | Shared | - |
Tile Drain Type | Hagen-Poiseuille | - |
Manning's Friction Coefficient | 0.0548 | m−1/3 s |
Hazen Williams Coefficient | 130 | m0.37 s−1 |
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Example Tile Drain Instructions
editAs an example, the following set of instructions, with prefix.tprops file Figure 5.13, could be inserted into the prefix.grok file to produce a horizontal tile drain:
use domain type
tile
properties file
prefix.tprops
clear chosen segments
choose segments polyline !Screen interval
2
15. 1. 2.
15. 29. 2.
new zone
1
clear chosen zones
choose zone number
1
read properties
tile one
clear chosen nodes
choose node !Tile drain intake
15. 15. 2.
create node set
tile
boundary condition
type
flux nodal
name
tile one
node set
tile
time value table
0.0 -2 !Pumping duration and rate
end
end
The tile domain example opens the property file prefix.tprops, shown in Figure 5.13, and creates a 28 m long screen between (15, 1, 2) and (15, 29, 2) with a pump intake located at (15, 15, 2). The tile one properties are read into grok and a steady pumping rate is set at -2 m3 s−1.
!------------------------------------------
tile one
radius
0.0108
!Coupling length and conductivity for dual node approach
coupling length
1.0e-4
coupling conductivity
.0023
!Infilled tiled drain with properties from the mprops file
infilled
Porous medium
end
- Figure 5.13: Sample tile drain domain property file prefix.tprops
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Radius
editScope: .grok .wprops
- TileScreenRadius Tile drain screen radius [L].
The radius of the screen interval of the tile drain.
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Infilled
editScope: .grok .wprops
This command should be included in the input file for an infilled tile drain.
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Hagen Poiseuille
editScope: .grok .wprops
This command should be included in the input for the Hagen Poiseuille flow option.
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Hazen Williams
editScope: .grok .wprops
This command should be included in the input file for the Hazen Williams flow option.
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Manning
editScope: .grok .wprops
This command should be included in the input file for the Manning flow option.
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Friction
editScope: .grok .wprops
- tile_friction Manning’s friction for tile drains.
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Hazen Williams coefficient
editScope: .grok .wprops
- tile_hw_coeffient Hazen-Williams coefficient for tile drains.
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Dual nodes for tiles
editScope: .grok .wprops
This instruction causes the tile drain flow scheme to use dual node approach.
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Coupling conductivity
editScope: .grok .wprops
- TilePropsCplCond Coupling conductivity for tile [L T−1].
Coupling conductivity parameter only required for the dual node approach for tile drains.
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Coupling length
editScope: .grok .wprops
- TilePropsCplLngth Coupling length for tile drain [L].
Coupling length parameter only required for the dual node approach for tile drains.
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