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! 

 

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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: 
/web/delft3dfm/forum

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

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** PLEASE TAG YOUR POST! **

 

 

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

 


Message Boards

RE: matching sediment fluxes through a closed contour and bed-level change

VG
V. Marco Gatto, modified 2 Years ago.

RE: matching sediment fluxes through a closed contour and bed-level change

Youngling Posts: 3 Join Date: 2/4/14 Recent Posts
I resolved the discrepancy with the orders of magnitude by multiplying the horizontal fluxes with the MORFAC (which evidently upscales only the bed level change), but I still find a factor ~2 difference. I thought the bed-slope effect could play a role, so I made sure that is deactived in the .mor file.
Any other ideas?
Bert Jagers, modified 2 Years ago.

RE: matching sediment fluxes through a closed contour and bed-level change

Jedi Knight Posts: 201 Join Date: 12/22/10 Recent Posts
V. Marco Gatto:
I resolved the discrepancy with the orders of magnitude ...


It looks like this message is a follow-up of a different one, so I'm sorry if I ask double questions. Where can I find the original description of discrepancies encountered. How do obtain the fluxes through the contour, and how do you compute the bed level change inside the contour?

V. Marco Gatto:
... by multiplying the horizontal fluxes with the MORFAC (which evidently upscales only the bed level change)


Indeed, the instantaneous fluxes do not include the morphological factor. Those fluxes should be comparable with the "instantaneous transport rates" in the field which don't include such numerical constructs. The cumulative fluxes do include the morphological factor as they are integrated over time which is influenced by MORFAC.

V. Marco Gatto:
... but I still find a factor ~2 difference. I thought the bed-slope effect could play a role, so I made sure that is deactived in the .mor file.
Any other ideas?


Bedslope effects should be included in the fluxes. Which fluxes are you using to perform the analysis?
Are you using the Filbal keyword (see Appendix A.1.4 Table A.6) for this analysis, or are you using fluxes for transects?
Is the horizontal Forester filter switched on? As these fluxes are not included in the output.

Best regards,

Bert