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

3 dimensional model with 3 layers

Binata Roy, modified 2 Years ago.

3 dimensional model with 3 layers

Youngling Posts: 4 Join Date: 11/6/16 Recent Posts
Hello everyone !! I am Binata Roy, currently working on setting up a 3-dimensional sediment model for Jamuna River. But I am facing several problems.

1. When I am trying to set up a 3-dimensional hydrodynamic model then the following errors are showing :

Part I - Initialisation Time Dep. Data module...
runid : three
Part II - Creating intermediate files...
Part III - Initialisation of the Execution module...
*** WARNING Double precision computation using reals of kind 8
Part IV - Reading complete MD-file...
error occured during reading phase, see tri-diag file for details.

Can anyone help me with this problem?

Ben Williams, modified 2 Years ago.

RE: 3 dimensional model with 3 layers

Jedi Knight Posts: 114 Join Date: 3/23/11 Recent Posts
Hi Binata,

You need to check the 'tri-diag' file in your modelling directory. This is a diagnostics file that often (but not always) gives you useful information on the error that is preventing your model from initialising.

As the error is during the initialisation of your model, rather than during the simulation itself, the error is due to the way you have set up the model rather than anything numerical (such as timestep etc). Common things that can result in an error, and are typically mentioned in your tri-diag file:

* An error in one of your boundary files
* The model starts at a time incompatible with the time stated in one of your input files
* A file is missing (grid, depth, etc)
* The simulation period is less than your specified smoothing time
* You have a problem with your Domain Decomposition (if using DD)