intro story D-Flow FM


D-Flow Flexible Mesh

D-Flow Flexible Mesh (D-Flow FM) is the new software engine for hydrodynamical simulations on unstructured grids in 1D-2D-3D. Together with the familiar curvilinear meshes from Delft3D 4, the unstructured grid can consist of triangles, pentagons (etc.) and 1D channel networks, all in one single mesh. It combines proven technology from the hydrodynamic engines of Delft3D 4 and SOBEK 2 and adds flexible administration, resulting in:

  • Easier 1D-2D-3D model coupling, intuitive setup of boundary conditions and meteorological forcings (amongst others).
  • More flexible 2D gridding in delta regions, river junctions, harbours, intertidal flats and more.
  • High performance by smart use of multicore architectures, and grid computing clusters.
An overview of the current developments can be found here.
The D-Flow FM - team would be delighted if you would participate in discussions on the generation of meshes, the specification of boundary conditions, the running of computations, and all kinds of other relevant topics. Feel free to share your smart questions and/or brilliant solutions! 


We have launched a new website (still under construction so expect continuous improvements) and a new forum dedicated to Delft3D Flexible Mesh.

Please follow this link to the new forum: 

Post your questions, issues, suggestions, difficulties related to our Delft3D Flexible Mesh Suite on the new forum.





Sub groups
D-Flow Flexible Mesh
Cohesive sediments & muddy systems


Message Boards

Different reference levels in Delft3d Flow (for water level simulation)

Esther Espinoza, modified 2 Years ago.

Different reference levels in Delft3d Flow (for water level simulation)

Padawan Posts: 25 Join Date: 4/6/17 Recent Posts
Hi I'm modelling water level for an estuary. The reference level of the bathymetry data I got was with respect to the MLWS (Mean Low Water Spring) because the data is taken for navigation purposes. The reference level of the amplitudes (time series) of tides, was with respect to the MWL (Mean Water Level). I modelled an example to see what happens, I got no error. But I'm still wondering if the error about modelling water level (MWL) with bathymetry respect to the MLWS generates significant changes in the results and how Delft3d works with reference levels. Do you know how this difference will influence the results or how can I correct this before or after the simulation? The area I'm modelling is kind of big.