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

Compiling Delft3d on OS X Yosemite successful but...

Yitping Kok, modified 1 Year ago.

Compiling Delft3d on OS X Yosemite successful but...

Youngling Posts: 2 Join Date: 11/6/17 Recent Posts
Hi all,

I followed this post and managed to successfully compile Delft3d on my OS X Yosemite (10.10.5) using necessary libraries I installed from MacPorts.

But when I test run the examples I have some runtime errors associated with date and time.

For example, when I run an example in example/01_standard (after modifying the paths in, I got the following:

Deltares, FLOW2D3D Version, Nov 14 2017, 23:11:10 entry Flow2D3D::Run

Part I - Initialisation Time Dep. Data module...
runid : f34
At line 92 of file vermdf.f90
Fortran runtime error: Bad value during integer read

The run generated 2 files before terminating,
td-diag.f34 and

The date and time in td-diag.f34 was bad (has unprintable ^@ characters, see below).

*** Deltares, FLOW2D3D Version, Nov 14 2017, 23:11:10
*** built from :
*** runid : f34
*** date,time : 2017-1^@-^@1,^@^@^@:21:07

I suspect this has to do with some differences in c/c++ time structures between Linux and OS X.
This is not surprising when I look again in the config.log file. In OS X, the -lrt library is not available and hence produced an error in the configuration stage.

Here's a snippet from my config.log.
configure:25486: checking for clock_gettime in -lrt
configure:25519: gcc-mp-7 -o conftest -O2 -I/opt/local/include -L/opt/local/li
ld: library not found for -lrt
collect2: error: ld returned 1 exit status

Can someone point me to some suspected parts of the code where this can be fixed?

Thanks very much for your attention and help.