[pjoynt]

Hi All,


I was wondering if anyone can provide any example control and ctrl files for how you might setup a porous berm breakwater in REEF3D CFD. We are currently trying to do some benchmarking against some other models (IH2VOF, OpenFOAM) but can't quite figure out how to define porosity similar to this paper:


https://reef3d.files.wordpress.com/2...breakwater.pdf


If anyone has any examples or guidance on which parameters to start with, that would be very helpful!


Thanks!

[kamath]

Hi pjoynt,

You need to define the different layers of the breakwater using a combination of B 270 (rectangular box, for the core layer) and B 281 (wedge in x-direction, for the armour and filter layers) in ctrl.txt. The paper you mention also uses Cm (from Eq 12) = 0.34 using B 260

Don't include anything in control.txt as the porous structure is defined through the commands in ctrl.txt.

Hope that helps

[pjoynt]

Hi Arun - thanks for the response!



Is there a specific order of operations that needs to be adhered to such that the various overlaps of geometry use a specific porosity? Should I define the core geometry first, then filter layer, then stones or does order not matter?


Cheers,
Patrick

[kamath]

Hi Patrick,

For a complex geometry as the berm breakwater, the order does matter.
The parts generated using the commands get overwritten. So therefore if you have a part that overlaps with a previously defined part, this latest command/part will overwrite the previously defined part.
So for example for one side of the breakwater (wedge) you will need to define three overlapping wedges to account for the three layers.

You will get a REEF3D_Porous-Object.vtp when you run reef3d.
Open this in Paraview and you can confirm that your input geometry is correct.
The different layers are not identified though, it will be one block.

You can further quality check, by running reef3d for one iteration, and just one part/ parts with some distance between them. You can then confirm that each of your parts is correct.

Attached is an oversimplified input file set for a rubble mound breakwater from Sasikumar et al. 2020

Hope that helps.

[pjoynt]

Originally Posted by kamath

Hi Patrick,

For a complex geometry as the berm breakwater, the order does matter.
The parts generated using the commands get overwritten. So therefore if you have a part that overlaps with a previously defined part, this latest command/part will overwrite the previously defined part.
So for example for one side of the breakwater (wedge) you will need to define three overlapping wedges to account for the three layers.

You will get a REEF3D_Porous-Object.vtp when you run reef3d.
Open this in Paraview and you can confirm that your input geometry is correct.
The different layers are not identified though, it will be one block.

You can further quality check, by running reef3d for one iteration, and just one part/ parts with some distance between them. You can then confirm that each of your parts is correct.

Attached is an oversimplified input file set for a rubble mound breakwater from Sasikumar et al. 2020

Hope that helps.

Very helpful! Thank you Arun!