====== FEFLOW ======

===== Exporting a GeoScene3D Layer Model to FEFLOW =====
 <font inherit/inherit;;#4e5f70;;inherit>FEFLOW is a finite-element based groundwater modeling software used to simulate subsurface flow and transport processes using geological layer models as a geometric framework. GeoScene3D can provide these geological layer models.</font>

//This workflow describes how to export a geological layer model from **GeoScene3D** and prepare it for use in **FEFLOW**.//
==== Requirements ====

  * GeoScene3D **Layer Model**  (.grd)
  * FEFLOW **Supermesh coordinate file**  (.dat)

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==== Step 1: Prepare the Layer Model in GeoScene3D ====

Open the Layer Model in GeoScene3D {{:geoscene3d:hydro_calculations:gs3d_fefow_start_layer_model.png?600}}//(For info on how to create a Layer Model see: [[https://wiki.geoscene3d.com/geoscene3d:building_a_layered_model|Building a layered model]])//

//Ensure that://

   * //All relevant layer surfaces are present//
  * //The model geometry is complete and consistent//—-

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==== Step 2: Prepare the Supermesh in FEFLOW ====

  - Open your FEFLOW model \\ {{:geoscene3d:hydro_calculations:feflow_supermesh.png?400}}
  - Create a **Supermesh**  covering the model area
  - Export the **mesh node coordinates**  to an ASCII file (.dat) \\ {{:geoscene3d:hydro_calculations:feflow_ascii.png?600}}

This file contains the **x–y coordinates**  of the mesh nodes and will later be enriched with elevation (z) values from GeoScene3D.

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==== Step 3: Merge Layer Model with FEFLOW mesh (GeoScene3D → FEFLOW) ====

  - In GeoScene3D, go to Hydro… \\ {{:geoscene3d:hydro_calculations:hydro.png?nolink&  }} \\  \\  \\ and choose Export Layer Model to FEFLOW… \\ {{:geoscene3d:hydro_calculations:hydro_export_layer_model_to_feflow.png?400}}
  - The export wizard opens – click ''Next >''  on the **welcome **page
  - Select the mesh coordinate file (.dat) exported from FEFLOW \\ {{:geoscene3d:hydro_calculations:mesh_coordinates.png?400}}
  - Choose the surfaces from the **Layer Model**  to be sampled \\ {{:geoscene3d:hydro_calculations:feflow_export_layermodel.png?400}}
  - Export the file and finish the wizard \\ {{:geoscene3d:hydro_calculations:feflow_export_finish.png?400}}

The exported file now contains **z-coordinates sampled from the GeoScene3D layer model**, linked to the original FEFLOW mesh nodes.

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==== Step 4: Import into FEFLOW ====

  - Import the updated .dat file into FEFLOW \\ {{:geoscene3d:hydro_calculations:new_mesh.png?600}}
  - The mesh nodes are now assigned elevations based on the GeoScene3D layer model \\ {{:geoscene3d:hydro_calculations:feflow_import.png?500}}


==== Result: ====

The geological surfaces from the GeoScene3D layer model are now incorporated to the FEFLOW model geo-metry. This enables groundwater flow and transport simulations in FEFLOW based on the geological model created in GeoScene3D.