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

a confusion on grid type

Hailiang Shen, modified 8 Years ago.

a confusion on grid type

Youngling Posts: 10 Join Date: 2/14/12 Recent Posts
Hello All,
I am trying to understand two types of grid: curvilinear grid, and orthogonal curvilinear grid.

In RGFGRID manual page 86 (the page no. at footnote), in "Restriction:" : "the grid must be orthogonal". My questions are:
1 RGFGRID is for curvilinear grid development, not just orthogonal curvilinear grid, right? So where else to store grid that are not orthogonal, other than the .grd file(s)?
2 What does "orthogonal" exactly mean in delft3d? Are every grid line perpendicular to each other? It seems very unlikely for curved boundary. May be I understand the term "orthogonal" in a wrong way.
3 Will QUICKIN work correctly on both curvilinear grid and orthogonal curvilinear grid? Will the resulting .dep file store corresponding point elevation correctly for the both types of grid?

Thanks for your inputs,